00000055132020Q2FALSE--12-3100000055132020-01-012020-06-300000005513us-gaap:CommonClassAMemberexch:XNYS2020-01-012020-06-300000005513exch:XNYSunm:A6250JuniorSubordinatedNotesDue2058Member2020-01-012020-06-30xbrli:shares00000055132020-07-27iso4217:USD00000055132020-06-3000000055132019-12-31iso4217:USDxbrli:shares00000055132020-04-012020-06-3000000055132019-04-012019-06-3000000055132019-01-012019-06-300000005513us-gaap:CommonStockMember2020-03-310000005513us-gaap:CommonStockMember2019-03-310000005513us-gaap:CommonStockMember2019-12-310000005513us-gaap:CommonStockMember2018-12-310000005513us-gaap:CommonStockMember2020-04-012020-06-300000005513us-gaap:CommonStockMember2019-04-012019-06-300000005513us-gaap:CommonStockMember2020-01-012020-06-300000005513us-gaap:CommonStockMember2019-01-012019-06-300000005513us-gaap:CommonStockMember2020-06-300000005513us-gaap:CommonStockMember2019-06-300000005513us-gaap:AdditionalPaidInCapitalMember2020-03-310000005513us-gaap:AdditionalPaidInCapitalMember2019-03-310000005513us-gaap:AdditionalPaidInCapitalMember2019-12-310000005513us-gaap:AdditionalPaidInCapitalMember2018-12-310000005513us-gaap:AdditionalPaidInCapitalMember2020-04-012020-06-300000005513us-gaap:AdditionalPaidInCapitalMember2019-04-012019-06-300000005513us-gaap:AdditionalPaidInCapitalMember2020-01-012020-06-300000005513us-gaap:AdditionalPaidInCapitalMember2019-01-012019-06-300000005513us-gaap:AdditionalPaidInCapitalMember2020-06-300000005513us-gaap:AdditionalPaidInCapitalMember2019-06-300000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2020-03-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2019-03-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2019-12-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2018-12-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2020-04-012020-06-300000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2019-04-012019-06-300000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2020-01-012020-06-300000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2019-01-012019-06-300000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2020-06-300000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2019-06-300000005513us-gaap:RetainedEarningsMember2020-03-310000005513us-gaap:RetainedEarningsMember2019-03-310000005513us-gaap:RetainedEarningsMember2019-12-310000005513us-gaap:RetainedEarningsMember2018-12-310000005513us-gaap:AccountingStandardsUpdate201613Membersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMemberus-gaap:RetainedEarningsMember2020-03-310000005513us-gaap:AccountingStandardsUpdate201602Membersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMemberus-gaap:RetainedEarningsMember2019-03-310000005513us-gaap:AccountingStandardsUpdate201613Membersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMemberus-gaap:RetainedEarningsMember2019-12-310000005513us-gaap:AccountingStandardsUpdate201602Membersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMemberus-gaap:RetainedEarningsMember2018-12-310000005513us-gaap:AccountingStandardsUpdate201613Membersrt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMemberus-gaap:RetainedEarningsMember2020-03-310000005513us-gaap:AccountingStandardsUpdate201602Membersrt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMemberus-gaap:RetainedEarningsMember2019-03-310000005513us-gaap:AccountingStandardsUpdate201613Membersrt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMemberus-gaap:RetainedEarningsMember2019-12-310000005513us-gaap:AccountingStandardsUpdate201602Membersrt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMemberus-gaap:RetainedEarningsMember2018-12-310000005513us-gaap:RetainedEarningsMember2020-04-012020-06-300000005513us-gaap:RetainedEarningsMember2019-04-012019-06-300000005513us-gaap:RetainedEarningsMember2020-01-012020-06-300000005513us-gaap:RetainedEarningsMember2019-01-012019-06-300000005513us-gaap:RetainedEarningsMember2020-06-300000005513us-gaap:RetainedEarningsMember2019-06-300000005513us-gaap:TreasuryStockMember2020-03-310000005513us-gaap:TreasuryStockMember2019-03-310000005513us-gaap:TreasuryStockMember2019-12-310000005513us-gaap:TreasuryStockMember2018-12-310000005513us-gaap:TreasuryStockMember2020-04-012020-06-300000005513us-gaap:TreasuryStockMember2019-04-012019-06-300000005513us-gaap:TreasuryStockMember2020-01-012020-06-300000005513us-gaap:TreasuryStockMember2019-01-012019-06-300000005513us-gaap:TreasuryStockMember2020-06-300000005513us-gaap:TreasuryStockMember2019-06-3000000055132019-06-3000000055132018-12-310000005513us-gaap:AccountingStandardsUpdate201613Member2019-12-310000005513us-gaap:AccountingStandardsUpdate201613Member2020-01-010000005513us-gaap:AccountingStandardsUpdate201613Membersrt:RestatementAdjustmentMember2020-01-0100000055132020-01-010000005513us-gaap:AccountingStandardsUpdate201602Membersrt:RestatementAdjustmentMember2019-01-01xbrli:pure0000005513us-gaap:FairValueInputsLevel1Member2020-06-300000005513unm:FairValueInputsOtherThanLevel1Member2020-06-300000005513us-gaap:FairValueInputsLevel2Memberunm:PricingServiceMember2020-06-300000005513us-gaap:FairValueInputsLevel2Memberunm:OtherObservableMarketDataMember2020-06-300000005513unm:FairValueInputsLevel2OrLevel3Member2020-06-300000005513unm:NotRedeemableMemberunm:PrivateCreditMemberus-gaap:PrivateEquityFundsMember2020-06-300000005513unm:PrivateCreditMemberus-gaap:PrivateEquityFundsMemberunm:Quarterlyafter2yearlockwith90daysnoticeMember2020-06-300000005513unm:PrivateCreditMemberus-gaap:PrivateEquityFundsMember2020-06-300000005513unm:NotRedeemableMemberus-gaap:PrivateEquityFundsMemberunm:PrivateEquityLimitedPartnershipMember2020-06-300000005513unm:NotRedeemableMemberunm:RealAssetsMemberus-gaap:PrivateEquityFundsMember2020-06-300000005513unm:RealAssetsMemberus-gaap:PrivateEquityFundsMemberunm:QuarterlyMember2020-06-300000005513unm:RealAssetsMemberus-gaap:PrivateEquityFundsMember2020-06-300000005513us-gaap:PrivateEquityFundsMember2020-06-300000005513unm:NotRedeemableMemberunm:PrivateCreditMemberus-gaap:PrivateEquityFundsMember2019-12-310000005513unm:PrivateCreditMemberus-gaap:PrivateEquityFundsMemberunm:Quarterlyafter2yearlockwith90daysnoticeMember2019-12-310000005513unm:PrivateCreditMemberus-gaap:PrivateEquityFundsMember2019-12-310000005513unm:NotRedeemableMemberus-gaap:PrivateEquityFundsMemberunm:PrivateEquityLimitedPartnershipMember2019-12-310000005513unm:NotRedeemableMemberunm:RealAssetsMemberus-gaap:PrivateEquityFundsMember2019-12-310000005513unm:RealAssetsMemberus-gaap:PrivateEquityFundsMemberunm:QuarterlyMember2019-12-310000005513unm:RealAssetsMemberus-gaap:PrivateEquityFundsMember2019-12-310000005513us-gaap:PrivateEquityFundsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2020-06-300000005513us-gaap:USTreasuryAndGovernmentMember2020-06-300000005513us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2020-06-300000005513us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMember2020-06-300000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2020-06-300000005513us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2020-06-300000005513us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMember2020-06-300000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PublicUtilityBondsMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:PublicUtilityBondsMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PublicUtilityBondsMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:PublicUtilityBondsMember2020-06-300000005513us-gaap:PublicUtilityBondsMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMember2020-06-300000005513us-gaap:AssetBackedSecuritiesMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMember2020-06-300000005513us-gaap:CorporateDebtSecuritiesMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:RedeemablePreferredStockMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:RedeemablePreferredStockMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:RedeemablePreferredStockMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:RedeemablePreferredStockMember2020-06-300000005513us-gaap:RedeemablePreferredStockMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMember2020-06-300000005513us-gaap:InterestRateSwapMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:ForwardContractsMember2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForwardContractsMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForwardContractsMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForwardContractsMember2020-06-300000005513us-gaap:ForwardContractsMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:CurrencySwapMember2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMember2020-06-300000005513us-gaap:CurrencySwapMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMember2020-06-300000005513us-gaap:CreditDefaultSwapMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PrivateEquityFundsMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:PrivateEquityFundsMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PrivateEquityFundsMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:PrivateEquityFundsMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:CurrencySwapMember2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:CurrencySwapMember2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMember2020-06-300000005513us-gaap:CurrencySwapMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2020-06-300000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMember2020-06-300000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2019-12-310000005513us-gaap:USTreasuryAndGovernmentMember2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2019-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PublicUtilityBondsMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:PublicUtilityBondsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PublicUtilityBondsMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:PublicUtilityBondsMember2019-12-310000005513us-gaap:PublicUtilityBondsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMember2019-12-310000005513us-gaap:AssetBackedSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMember2019-12-310000005513us-gaap:CorporateDebtSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:RedeemablePreferredStockMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:RedeemablePreferredStockMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:RedeemablePreferredStockMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:RedeemablePreferredStockMember2019-12-310000005513us-gaap:RedeemablePreferredStockMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:CurrencySwapMember2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMember2019-12-310000005513us-gaap:CurrencySwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMember2019-12-310000005513us-gaap:CreditDefaultSwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PrivateEquityFundsMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:PrivateEquityFundsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PrivateEquityFundsMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:PrivateEquityFundsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:CurrencySwapMember2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:CurrencySwapMember2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMember2019-12-310000005513us-gaap:CurrencySwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-12-310000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMember2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2020-03-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2020-04-012020-06-300000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2020-06-300000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2020-03-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2020-04-012020-06-300000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2020-06-300000005513us-gaap:PublicUtilityBondsMember2020-03-310000005513us-gaap:PublicUtilityBondsMember2020-04-012020-06-300000005513us-gaap:PublicUtilityBondsMember2020-06-300000005513us-gaap:AssetBackedSecuritiesMember2020-03-310000005513us-gaap:AssetBackedSecuritiesMember2020-04-012020-06-300000005513us-gaap:AssetBackedSecuritiesMember2020-06-300000005513us-gaap:CorporateDebtSecuritiesMember2020-03-310000005513us-gaap:CorporateDebtSecuritiesMember2020-04-012020-06-300000005513us-gaap:CorporateDebtSecuritiesMember2020-06-300000005513us-gaap:DebtSecuritiesMember2020-03-310000005513us-gaap:DebtSecuritiesMember2020-04-012020-06-300000005513us-gaap:DebtSecuritiesMember2020-06-300000005513us-gaap:EquitySecuritiesMember2020-03-310000005513us-gaap:EquitySecuritiesMember2020-04-012020-06-300000005513us-gaap:EquitySecuritiesMember2020-06-300000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2020-03-310000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2020-04-012020-06-300000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2019-03-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2019-04-012019-06-300000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2019-06-300000005513us-gaap:PublicUtilityBondsMember2019-03-310000005513us-gaap:PublicUtilityBondsMember2019-04-012019-06-300000005513us-gaap:PublicUtilityBondsMember2019-06-300000005513us-gaap:CorporateDebtSecuritiesMember2019-03-310000005513us-gaap:CorporateDebtSecuritiesMember2019-04-012019-06-300000005513us-gaap:CorporateDebtSecuritiesMember2019-06-300000005513us-gaap:RedeemablePreferredStockMember2019-03-310000005513us-gaap:RedeemablePreferredStockMember2019-01-012019-06-300000005513us-gaap:RedeemablePreferredStockMember2019-04-012019-06-300000005513us-gaap:RedeemablePreferredStockMember2019-06-300000005513us-gaap:DebtSecuritiesMember2019-03-310000005513us-gaap:DebtSecuritiesMember2019-04-012019-06-300000005513us-gaap:DebtSecuritiesMember2019-06-300000005513us-gaap:EquitySecuritiesMember2019-03-310000005513us-gaap:EquitySecuritiesMember2019-04-012019-06-300000005513us-gaap:EquitySecuritiesMember2019-06-300000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-03-310000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-04-012019-06-300000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-06-300000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2020-01-012020-06-300000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2019-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2020-01-012020-06-300000005513us-gaap:PublicUtilityBondsMember2019-12-310000005513us-gaap:PublicUtilityBondsMember2020-01-012020-06-300000005513us-gaap:AssetBackedSecuritiesMember2019-12-310000005513us-gaap:AssetBackedSecuritiesMember2020-01-012020-06-300000005513us-gaap:CorporateDebtSecuritiesMember2019-12-310000005513us-gaap:CorporateDebtSecuritiesMember2020-01-012020-06-300000005513us-gaap:DebtSecuritiesMember2019-12-310000005513us-gaap:DebtSecuritiesMember2020-01-012020-06-300000005513us-gaap:EquitySecuritiesMember2019-12-310000005513us-gaap:EquitySecuritiesMember2020-01-012020-06-300000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2020-01-012020-06-300000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2018-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2019-01-012019-06-300000005513us-gaap:PublicUtilityBondsMember2018-12-310000005513us-gaap:PublicUtilityBondsMember2019-01-012019-06-300000005513us-gaap:CorporateDebtSecuritiesMember2018-12-310000005513us-gaap:CorporateDebtSecuritiesMember2019-01-012019-06-300000005513us-gaap:RedeemablePreferredStockMember2018-12-310000005513us-gaap:DebtSecuritiesMember2018-12-310000005513us-gaap:DebtSecuritiesMember2019-01-012019-06-300000005513us-gaap:EquitySecuritiesMember2018-12-310000005513us-gaap:EquitySecuritiesMember2019-01-012019-06-300000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2018-12-310000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-01-012019-06-300000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:PublicUtilityBondsMemberus-gaap:FairValueInputsLevel3Member2020-06-30utr:Rate0000005513us-gaap:MarketApproachValuationTechniqueMembersrt:MinimumMemberus-gaap:PublicUtilityBondsMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMembersrt:MaximumMemberus-gaap:PublicUtilityBondsMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMembersrt:WeightedAverageMemberus-gaap:PublicUtilityBondsMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMembersrt:MinimumMemberus-gaap:PublicUtilityBondsMemberunm:MeasurementInputDiscountForSizeMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMembersrt:MaximumMemberus-gaap:PublicUtilityBondsMemberunm:MeasurementInputDiscountForSizeMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMembersrt:WeightedAverageMemberus-gaap:PublicUtilityBondsMemberunm:MeasurementInputDiscountForSizeMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMembersrt:MinimumMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMembersrt:MaximumMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:CorporateDebtSecuritiesMembersrt:WeightedAverageMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:MeasurementInputEntityCreditRiskMembersrt:MinimumMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:MeasurementInputEntityCreditRiskMembersrt:MaximumMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:MeasurementInputEntityCreditRiskMemberus-gaap:CorporateDebtSecuritiesMembersrt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMembersrt:MinimumMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMembersrt:MaximumMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MeasurementInputComparabilityAdjustmentMemberus-gaap:MarketApproachValuationTechniqueMemberus-gaap:CorporateDebtSecuritiesMembersrt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:EquitySecuritiesMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:DerivativeFinancialInstrumentsLiabilitiesMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:MarketApproachValuationTechniqueMembersrt:MinimumMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:MarketApproachValuationTechniqueMembersrt:MaximumMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:CorporateDebtSecuritiesMembersrt:WeightedAverageMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:MeasurementInputEntityCreditRiskMembersrt:MinimumMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:MeasurementInputEntityCreditRiskMembersrt:MaximumMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:MeasurementInputEntityCreditRiskMemberus-gaap:CorporateDebtSecuritiesMembersrt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:MarketApproachValuationTechniqueMemberus-gaap:EquitySecuritiesMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:DerivativeFinancialInstrumentsLiabilitiesMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:FairValueInputsLevel1Member2020-06-300000005513us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:FairValueInputsLevel2Member2020-06-300000005513us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:FairValueInputsLevel3Member2020-06-300000005513us-gaap:FairValueMeasurementsNonrecurringMember2020-06-300000005513us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:FairValueInputsLevel2Member2019-12-310000005513us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasurementsNonrecurringMember2019-12-310000005513us-gaap:AllOtherCorporateBondsMember2020-06-300000005513us-gaap:DebtSecuritiesMember2020-06-300000005513us-gaap:AllOtherCorporateBondsMember2019-12-310000005513us-gaap:DebtSecuritiesMember2019-12-310000005513unm:AvailableForSaleSecuritiesUnrealizedGainPositionFairValueMember2020-06-300000005513unm:AvailableForSaleSecuritiesUnrealizedLossPositionFairValueMember2020-06-300000005513unm:AvailableForSaleSecuritiesUnrealizedGainPositionFairValueMember2019-12-310000005513unm:AvailableForSaleSecuritiesUnrealizedLossPositionFairValueMember2019-12-310000005513us-gaap:ExternalCreditRatingInvestmentGradeMember2020-06-300000005513us-gaap:ExternalCreditRatingNonInvestmentGradeMember2020-06-300000005513us-gaap:AllOtherCorporateBondsMember2020-03-310000005513us-gaap:AllOtherCorporateBondsMember2020-04-012020-06-300000005513us-gaap:AllOtherCorporateBondsMember2020-01-012020-06-300000005513us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember2020-06-300000005513unm:TaxCreditPartnershipMemberus-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember2020-06-300000005513us-gaap:EquityMethodInvestmentsMemberus-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember2020-06-300000005513us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember2019-12-310000005513unm:TaxCreditPartnershipMemberus-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember2019-12-310000005513us-gaap:EquityMethodInvestmentsMemberus-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember2019-12-310000005513us-gaap:CommercialRealEstateMember2020-06-300000005513us-gaap:CommercialRealEstateMember2019-12-310000005513srt:ApartmentBuildingMember2020-06-300000005513srt:ApartmentBuildingMember2019-12-310000005513srt:IndustrialPropertyMember2020-06-300000005513srt:IndustrialPropertyMember2019-12-310000005513srt:OfficeBuildingMember2020-06-300000005513srt:OfficeBuildingMember2019-12-310000005513srt:RetailSiteMember2020-06-300000005513srt:RetailSiteMember2019-12-310000005513srt:OtherPropertyMember2020-06-300000005513srt:OtherPropertyMember2019-12-310000005513unm:TotalMember2020-06-300000005513unm:TotalMember2019-12-310000005513unm:NewEnglandMember2020-06-300000005513unm:NewEnglandMember2019-12-310000005513unm:MiddleAtlanticMember2020-06-300000005513unm:MiddleAtlanticMember2019-12-310000005513unm:EastNorthCentralMember2020-06-300000005513unm:EastNorthCentralMember2019-12-310000005513unm:WestNorthCentralMember2020-06-300000005513unm:WestNorthCentralMember2019-12-310000005513unm:SouthAtlanticMember2020-06-300000005513unm:SouthAtlanticMember2019-12-310000005513unm:EastSouthCentralMember2020-06-300000005513unm:EastSouthCentralMember2019-12-310000005513unm:WestSouthCentralMember2020-06-300000005513unm:WestSouthCentralMember2019-12-310000005513unm:MountainMember2020-06-300000005513unm:MountainMember2019-12-310000005513unm:PacificMember2020-06-300000005513unm:PacificMember2019-12-310000005513unm:TotalMember2020-06-300000005513unm:TotalMember2019-12-310000005513unm:CreditRatingMember2020-06-300000005513unm:CreditRatingMember2019-12-310000005513unm:BBBCreditRatingMember2020-06-300000005513unm:BBBCreditRatingMember2019-12-310000005513unm:BBCreditRatingMember2020-06-300000005513unm:BBCreditRatingMember2019-12-310000005513unm:BCreditRatingMember2020-06-300000005513unm:BCreditRatingMember2019-12-310000005513unm:TotalMember2020-06-300000005513unm:TotalMember2019-12-310000005513unm:LoanToValueRatioBelowOrEqualTo65PercentMember2020-06-300000005513unm:LoanToValueRatioBelowOrEqualTo65PercentMember2019-12-310000005513unm:LoanToValueRatioAbove65To75PercentMember2020-06-300000005513unm:LoanToValueRatioAbove65To75PercentMember2019-12-310000005513unm:LoanToValueRatioAbove75To85PercentMember2020-06-300000005513unm:LoanToValueRatioAbove75To85PercentMember2019-12-310000005513unm:LoanToValueRatioAbove85PercentMember2020-06-300000005513unm:LoanToValueRatioAbove85PercentMember2019-12-310000005513unm:TotalMember2020-06-300000005513unm:TotalMember2019-12-310000005513us-gaap:CommercialRealEstateMemberunm:CreditRatingMember2020-06-300000005513us-gaap:CommercialRealEstateMemberunm:BBBCreditRatingMember2020-06-300000005513us-gaap:CommercialRealEstateMemberunm:BBCreditRatingMember2020-06-300000005513us-gaap:CommercialRealEstateMemberunm:BCreditRatingMember2020-06-300000005513us-gaap:CommercialRealEstateMemberunm:OriginatedFiveOrMoreYearsBeforeLastFiscalYearMember2020-06-300000005513unm:OriginatedFourYearsBeforeLastFiscalYearMemberus-gaap:CommercialRealEstateMember2020-06-300000005513unm:OriginatedThreeYearsBeforeLastFiscalYearMemberus-gaap:CommercialRealEstateMember2020-06-300000005513us-gaap:CommercialRealEstateMemberunm:OriginatedTwoYearsBeforeLastFiscalYearMember2020-06-300000005513unm:OriginatedInFiscalYearBeforeLatestFiscalYearMemberus-gaap:CommercialRealEstateMember2020-06-300000005513us-gaap:CommercialRealEstateMemberunm:OriginatedInCurrentFiscalYearMember2020-06-300000005513unm:OriginatedFiveOrMoreYearsBeforeLastFiscalYearMember2020-06-300000005513unm:OriginatedFourYearsBeforeLastFiscalYearMember2020-06-300000005513unm:OriginatedThreeYearsBeforeLastFiscalYearMember2020-06-300000005513unm:OriginatedTwoYearsBeforeLastFiscalYearMember2020-06-300000005513unm:OriginatedInFiscalYearBeforeLatestFiscalYearMember2020-06-300000005513unm:OriginatedInCurrentFiscalYearMember2020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioBelowOrEqualTo65PercentMember2020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove65To75PercentMember2020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove75To85PercentMember2020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove85PercentMember2020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioBelowOrEqualTo65PercentMember2020-03-310000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioBelowOrEqualTo65PercentMember2020-04-012020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove65To75PercentMember2020-03-310000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove65To75PercentMember2020-04-012020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove75To85PercentMember2020-03-310000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove75To85PercentMember2020-04-012020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove85PercentMember2020-03-310000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove85PercentMember2020-04-012020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioTotalMember2020-03-310000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioTotalMember2020-04-012020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioTotalMember2020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioBelowOrEqualTo65PercentMember2020-01-010000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioBelowOrEqualTo65PercentMember2020-01-012020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove65To75PercentMember2020-01-010000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove65To75PercentMember2020-01-012020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove75To85PercentMember2020-01-010000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove75To85PercentMember2020-01-012020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove85PercentMember2020-01-010000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioAbove85PercentMember2020-01-012020-06-300000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioTotalMember2020-01-010000005513us-gaap:CommercialRealEstateMemberunm:LoanToValueRatioTotalMember2020-01-012020-06-30unm:Integer0000005513us-gaap:CommercialRealEstateMember2020-01-012020-06-300000005513us-gaap:CommercialRealEstateMember2019-04-012019-06-300000005513us-gaap:CommercialRealEstateMember2019-01-012019-06-300000005513us-gaap:CommercialRealEstateMember2020-04-012020-06-300000005513unm:UnfundedMortgageLoanCommitmentsMember2020-06-300000005513unm:OffBalanceSheetAmountMember2019-12-310000005513us-gaap:MortgageBackedSecuritiesMember2020-06-300000005513us-gaap:MortgageBackedSecuritiesMember2019-12-310000005513us-gaap:OverTheCounterMember2020-06-300000005513us-gaap:OverTheCounterMember2019-12-310000005513us-gaap:DebtSecuritiesMember2020-04-012020-06-300000005513us-gaap:DebtSecuritiesMember2019-04-012019-06-300000005513us-gaap:DebtSecuritiesMember2020-01-012020-06-300000005513us-gaap:DebtSecuritiesMember2019-01-012019-06-300000005513us-gaap:DerivativeMember2020-04-012020-06-300000005513us-gaap:DerivativeMember2019-04-012019-06-300000005513us-gaap:DerivativeMember2020-01-012020-06-300000005513us-gaap:DerivativeMember2019-01-012019-06-300000005513us-gaap:MortgageReceivablesMember2020-04-012020-06-300000005513us-gaap:MortgageReceivablesMember2019-04-012019-06-300000005513us-gaap:MortgageReceivablesMember2020-01-012020-06-300000005513us-gaap:MortgageReceivablesMember2019-01-012019-06-300000005513us-gaap:PolicyLoansMember2020-04-012020-06-300000005513us-gaap:PolicyLoansMember2019-04-012019-06-300000005513us-gaap:PolicyLoansMember2020-01-012020-06-300000005513us-gaap:PolicyLoansMember2019-01-012019-06-300000005513us-gaap:EquitySecuritiesMember2020-04-012020-06-300000005513us-gaap:EquitySecuritiesMember2019-04-012019-06-300000005513us-gaap:EquitySecuritiesMember2020-01-012020-06-300000005513us-gaap:EquitySecuritiesMember2019-01-012019-06-300000005513srt:PartnershipInterestMember2020-04-012020-06-300000005513srt:PartnershipInterestMember2019-04-012019-06-300000005513srt:PartnershipInterestMember2020-01-012020-06-300000005513srt:PartnershipInterestMember2019-01-012019-06-300000005513us-gaap:OtherLongTermInvestmentsMember2020-04-012020-06-300000005513us-gaap:OtherLongTermInvestmentsMember2019-04-012019-06-300000005513us-gaap:OtherLongTermInvestmentsMember2020-01-012020-06-300000005513us-gaap:OtherLongTermInvestmentsMember2019-01-012019-06-300000005513us-gaap:ShortTermInvestmentsMember2020-04-012020-06-300000005513us-gaap:ShortTermInvestmentsMember2019-04-012019-06-300000005513us-gaap:ShortTermInvestmentsMember2020-01-012020-06-300000005513us-gaap:ShortTermInvestmentsMember2019-01-012019-06-300000005513unm:CreditExposureMember2020-06-300000005513unm:CreditExposureMember2019-12-310000005513us-gaap:CashMember2020-06-300000005513us-gaap:CashMember2019-12-310000005513us-gaap:AvailableforsaleSecuritiesMember2020-06-300000005513us-gaap:AvailableforsaleSecuritiesMember2019-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:InterestRateSwapMember2019-03-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2019-03-310000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2019-03-310000005513us-gaap:ForwardContractsMember2019-03-3100000055132019-03-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:InterestRateSwapMember2019-04-012019-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2019-04-012019-06-300000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2019-04-012019-06-300000005513us-gaap:ForwardContractsMember2019-04-012019-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:InterestRateSwapMember2019-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2019-06-300000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2019-06-300000005513us-gaap:ForwardContractsMember2019-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:InterestRateSwapMember2018-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2018-12-310000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2018-12-310000005513us-gaap:ForwardContractsMember2018-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:InterestRateSwapMember2019-01-012019-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2019-01-012019-06-300000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2019-01-012019-06-300000005513us-gaap:ForwardContractsMember2019-01-012019-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:InterestRateSwapMember2020-03-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2020-03-310000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2020-03-310000005513us-gaap:ForwardContractsMember2020-03-3100000055132020-03-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:InterestRateSwapMember2020-04-012020-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2020-04-012020-06-300000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2020-04-012020-06-300000005513us-gaap:ForwardContractsMember2020-04-012020-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:InterestRateSwapMember2020-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2020-06-300000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2020-06-300000005513us-gaap:ForwardContractsMember2020-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:InterestRateSwapMember2019-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2019-12-310000005513us-gaap:ForwardContractsMember2019-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:InterestRateSwapMember2020-01-012020-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2020-01-012020-06-300000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2020-01-012020-06-300000005513us-gaap:ForwardContractsMember2020-01-012020-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMember2019-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMember2020-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMember2020-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2019-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:AvailableforsaleSecuritiesMemberus-gaap:FairValueHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateSwapMember2020-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:AvailableforsaleSecuritiesMemberus-gaap:FairValueHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMemberus-gaap:LongTermDebtMember2020-06-300000005513us-gaap:FairValueHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMemberus-gaap:LongTermDebtMember2019-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2020-06-300000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2020-06-300000005513us-gaap:NondesignatedMemberus-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:ForwardContractsMember2020-06-300000005513us-gaap:NondesignatedMemberus-gaap:ForwardContractsMember2019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:OtherLongTermInvestmentsMember2020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:OtherLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMember2020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:OtherLongTermInvestmentsMember2020-06-300000005513us-gaap:OtherLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMember2020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:OtherLongTermInvestmentsMember2020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:OtherLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMember2020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:OtherLongTermInvestmentsMember2020-06-300000005513us-gaap:OtherLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMember2020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:OtherLongTermInvestmentsMember2020-06-300000005513us-gaap:OtherLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMember2020-06-300000005513us-gaap:NondesignatedMemberus-gaap:CreditRiskContractMemberus-gaap:OtherLongTermInvestmentsMember2020-06-300000005513us-gaap:OtherLiabilitiesMemberus-gaap:NondesignatedMemberus-gaap:CreditRiskContractMember2020-06-300000005513us-gaap:NondesignatedMemberus-gaap:ForwardContractsMemberus-gaap:OtherLongTermInvestmentsMember2020-06-300000005513us-gaap:OtherLiabilitiesMemberus-gaap:NondesignatedMemberus-gaap:ForwardContractsMember2020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMemberus-gaap:OtherLongTermInvestmentsMember2020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:OtherLiabilitiesMemberus-gaap:NondesignatedMember2020-06-300000005513us-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMemberus-gaap:OtherLongTermInvestmentsMember2020-06-300000005513us-gaap:OtherLiabilitiesMemberus-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2020-06-300000005513us-gaap:NondesignatedMemberus-gaap:OtherLongTermInvestmentsMember2020-06-300000005513us-gaap:OtherLiabilitiesMemberus-gaap:NondesignatedMember2020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:OtherLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMember2019-12-310000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:OtherLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:OtherLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMember2019-12-310000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:OtherLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMember2019-12-310000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:OtherLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:CreditRiskContractMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:OtherLiabilitiesMemberus-gaap:NondesignatedMemberus-gaap:CreditRiskContractMember2019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:OtherLiabilitiesMemberus-gaap:NondesignatedMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:OtherLiabilitiesMemberus-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:OtherLiabilitiesMemberus-gaap:NondesignatedMember2019-12-310000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:InvestmentIncomeMember2020-04-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:GainLossOnInvestmentsMember12020-04-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestExpenseMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMember2020-04-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:InvestmentIncomeMember2019-04-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:GainLossOnInvestmentsMember12019-04-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestExpenseMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMember2019-04-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InvestmentIncomeMember2020-04-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:GainLossOnInvestmentsMember12020-04-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestExpenseMemberus-gaap:CashFlowHedgingMember2020-04-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InvestmentIncomeMember2019-04-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:GainLossOnInvestmentsMember12019-04-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestExpenseMemberus-gaap:CashFlowHedgingMember2019-04-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:InvestmentIncomeMember2020-04-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:GainLossOnInvestmentsMember12020-04-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestExpenseMemberus-gaap:InterestRateSwapMember2020-04-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:InvestmentIncomeMember2019-04-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:GainLossOnInvestmentsMember12019-04-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestExpenseMemberus-gaap:InterestRateSwapMember2019-04-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InvestmentIncomeMember2020-04-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:GainLossOnInvestmentsMember12020-04-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestExpenseMember2020-04-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InvestmentIncomeMember2019-04-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:GainLossOnInvestmentsMember12019-04-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestExpenseMember2019-04-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:InvestmentIncomeMember2020-01-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:GainLossOnInvestmentsMember12020-01-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestExpenseMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMember2020-01-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:InvestmentIncomeMember2019-01-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:GainLossOnInvestmentsMember12019-01-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestExpenseMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMember2019-01-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InvestmentIncomeMember2020-01-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:GainLossOnInvestmentsMember12020-01-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestExpenseMemberus-gaap:CashFlowHedgingMember2020-01-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InvestmentIncomeMember2019-01-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:GainLossOnInvestmentsMember12019-01-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestExpenseMemberus-gaap:CashFlowHedgingMember2019-01-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:InvestmentIncomeMember2020-01-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:GainLossOnInvestmentsMember12020-01-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestExpenseMemberus-gaap:InterestRateSwapMember2020-01-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:InvestmentIncomeMember2019-01-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:GainLossOnInvestmentsMember12019-01-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestExpenseMemberus-gaap:InterestRateSwapMember2019-01-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InvestmentIncomeMember2020-01-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:GainLossOnInvestmentsMember12020-01-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestExpenseMember2020-01-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InvestmentIncomeMember2019-01-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:GainLossOnInvestmentsMember12019-01-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:FairValueHedgingMemberus-gaap:InterestExpenseMember2019-01-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMember2020-04-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMember2019-04-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMember2020-01-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestRateSwapMember2019-01-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMember2020-04-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMember2019-04-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMember2020-01-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMember2019-01-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMember2020-04-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMember2019-04-012019-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMember2020-01-012020-06-300000005513us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:CashFlowHedgingMember2019-01-012019-06-300000005513us-gaap:NondesignatedMemberus-gaap:CreditDefaultSwapMember2020-04-012020-06-300000005513us-gaap:NondesignatedMemberus-gaap:CreditDefaultSwapMember2019-04-012019-06-300000005513us-gaap:NondesignatedMemberus-gaap:CreditDefaultSwapMember2020-01-012020-06-300000005513us-gaap:NondesignatedMemberus-gaap:CreditDefaultSwapMember2019-01-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2020-04-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2019-04-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2020-01-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2019-01-012019-06-300000005513us-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2020-04-012020-06-300000005513us-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-04-012019-06-300000005513us-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2020-01-012020-06-300000005513us-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-01-012019-06-300000005513us-gaap:NondesignatedMember2020-04-012020-06-300000005513us-gaap:NondesignatedMember2019-04-012019-06-300000005513us-gaap:NondesignatedMember2020-01-012020-06-300000005513us-gaap:NondesignatedMember2019-01-012019-06-300000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2020-03-310000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2020-03-310000005513us-gaap:AccumulatedTranslationAdjustmentMember2020-03-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2020-03-310000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2020-04-012020-06-300000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2020-04-012020-06-300000005513us-gaap:AccumulatedTranslationAdjustmentMember2020-04-012020-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2020-04-012020-06-300000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2020-06-300000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2020-06-300000005513us-gaap:AccumulatedTranslationAdjustmentMember2020-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2020-06-300000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2019-03-310000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-03-310000005513us-gaap:AccumulatedTranslationAdjustmentMember2019-03-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2019-03-310000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2019-04-012019-06-300000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-04-012019-06-300000005513us-gaap:AccumulatedTranslationAdjustmentMember2019-04-012019-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2019-04-012019-06-300000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2019-06-300000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-06-300000005513us-gaap:AccumulatedTranslationAdjustmentMember2019-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2019-06-300000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2019-12-310000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-12-310000005513us-gaap:AccumulatedTranslationAdjustmentMember2019-12-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2019-12-310000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2020-01-012020-06-300000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2020-01-012020-06-300000005513us-gaap:AccumulatedTranslationAdjustmentMember2020-01-012020-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2020-01-012020-06-300000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2018-12-310000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2018-12-310000005513us-gaap:AccumulatedTranslationAdjustmentMember2018-12-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2018-12-310000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2019-01-012019-06-300000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-01-012019-06-300000005513us-gaap:AccumulatedTranslationAdjustmentMember2019-01-012019-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2019-01-012019-06-300000005513us-gaap:DebtSecuritiesMember2020-06-300000005513us-gaap:DebtSecuritiesMember2020-03-310000005513us-gaap:DebtSecuritiesMember2019-12-310000005513us-gaap:DebtSecuritiesMember2020-04-012020-06-300000005513us-gaap:DebtSecuritiesMember2020-01-012020-06-300000005513unm:DeferredAcquisitionCostsMember2020-06-300000005513unm:DeferredAcquisitionCostsMember2020-03-310000005513unm:DeferredAcquisitionCostsMember2019-12-310000005513unm:DeferredAcquisitionCostsMember2020-04-012020-06-300000005513unm:DeferredAcquisitionCostsMember2020-01-012020-06-300000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2020-06-300000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2020-03-310000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2019-12-310000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2020-04-012020-06-300000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2020-01-012020-06-300000005513us-gaap:ReinsuranceRecoverableMember2020-06-300000005513us-gaap:ReinsuranceRecoverableMember2020-03-310000005513us-gaap:ReinsuranceRecoverableMember2019-12-310000005513us-gaap:ReinsuranceRecoverableMember2020-04-012020-06-300000005513us-gaap:ReinsuranceRecoverableMember2020-01-012020-06-300000005513us-gaap:DeferredIncomeTaxChargesMember2020-06-300000005513us-gaap:DeferredIncomeTaxChargesMember2020-03-310000005513us-gaap:DeferredIncomeTaxChargesMember2019-12-310000005513us-gaap:DeferredIncomeTaxChargesMember2020-04-012020-06-300000005513us-gaap:DeferredIncomeTaxChargesMember2020-01-012020-06-300000005513us-gaap:DebtSecuritiesMember2019-06-300000005513us-gaap:DebtSecuritiesMember2019-03-310000005513us-gaap:DebtSecuritiesMember2018-12-310000005513us-gaap:DebtSecuritiesMember2019-04-012019-06-300000005513us-gaap:DebtSecuritiesMember2019-01-012019-06-300000005513unm:DeferredAcquisitionCostsMember2019-06-300000005513unm:DeferredAcquisitionCostsMember2019-03-310000005513unm:DeferredAcquisitionCostsMember2018-12-310000005513unm:DeferredAcquisitionCostsMember2019-04-012019-06-300000005513unm:DeferredAcquisitionCostsMember2019-01-012019-06-300000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2019-06-300000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2019-03-310000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2018-12-310000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2019-04-012019-06-300000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2019-01-012019-06-300000005513us-gaap:ReinsuranceRecoverableMember2019-06-300000005513us-gaap:ReinsuranceRecoverableMember2019-03-310000005513us-gaap:ReinsuranceRecoverableMember2018-12-310000005513us-gaap:ReinsuranceRecoverableMember2019-04-012019-06-300000005513us-gaap:ReinsuranceRecoverableMember2019-01-012019-06-300000005513us-gaap:DeferredIncomeTaxChargesMember2019-06-300000005513us-gaap:DeferredIncomeTaxChargesMember2019-03-310000005513us-gaap:DeferredIncomeTaxChargesMember2018-12-310000005513us-gaap:DeferredIncomeTaxChargesMember2019-04-012019-06-300000005513us-gaap:DeferredIncomeTaxChargesMember2019-01-012019-06-300000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2020-04-012020-06-300000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2019-04-012019-06-300000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2020-01-012020-06-300000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2019-01-012019-06-300000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:InterestRateSwapMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2020-04-012020-06-300000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:InterestRateSwapMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-04-012019-06-300000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:InterestRateSwapMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2020-01-012020-06-300000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:InterestRateSwapMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-01-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2020-04-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-04-012019-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2020-01-012020-06-300000005513us-gaap:ForeignExchangeContractMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-01-012019-06-300000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2020-04-012020-06-300000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-04-012019-06-300000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2020-01-012020-06-300000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-01-012019-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2020-04-012020-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2019-04-012019-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2020-01-012020-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2019-01-012019-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2020-04-012020-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2019-04-012019-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2020-01-012020-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2019-01-012019-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2020-04-012020-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2019-04-012019-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2020-01-012020-06-300000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2019-01-012019-06-300000005513unm:AmountRelatedtoInterestMember2020-01-012020-06-300000005513unm:AmountRelatedtoInterestMember2019-01-012019-06-300000005513unm:IncurredClaimsMember2020-01-012020-06-300000005513unm:IncurredClaimsMember2019-01-012019-06-300000005513unm:ForeignCurrencyMember2020-01-012020-06-300000005513unm:ForeignCurrencyMember2019-01-012019-06-300000005513us-gaap:OperatingExpenseMember2020-01-012020-06-300000005513us-gaap:OperatingExpenseMember2019-01-012019-06-300000005513unm:GroupLongTermDisabilityMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-04-012020-06-300000005513unm:GroupLongTermDisabilityMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-04-012019-06-300000005513unm:GroupLongTermDisabilityMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-01-012020-06-300000005513unm:GroupLongTermDisabilityMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-01-012019-06-300000005513unm:GroupShortTermDisabilityMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-04-012020-06-300000005513unm:GroupShortTermDisabilityMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-04-012019-06-300000005513unm:GroupShortTermDisabilityMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-01-012020-06-300000005513unm:GroupShortTermDisabilityMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-01-012019-06-300000005513unm:GroupLifeMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-04-012020-06-300000005513unm:GroupLifeMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-04-012019-06-300000005513unm:GroupLifeMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-01-012020-06-300000005513unm:GroupLifeMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-01-012019-06-300000005513us-gaap:OperatingSegmentsMemberunm:UnumUsMemberunm:AccidentalDeathDismembermentMember2020-04-012020-06-300000005513us-gaap:OperatingSegmentsMemberunm:UnumUsMemberunm:AccidentalDeathDismembermentMember2019-04-012019-06-300000005513us-gaap:OperatingSegmentsMemberunm:UnumUsMemberunm:AccidentalDeathDismembermentMember2020-01-012020-06-300000005513us-gaap:OperatingSegmentsMemberunm:UnumUsMemberunm:AccidentalDeathDismembermentMember2019-01-012019-06-300000005513unm:IndividualDisabilityInsuranceMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-04-012020-06-300000005513unm:IndividualDisabilityInsuranceMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-04-012019-06-300000005513unm:IndividualDisabilityInsuranceMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-01-012020-06-300000005513unm:IndividualDisabilityInsuranceMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-01-012019-06-300000005513unm:VoluntaryBenefitsMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-04-012020-06-300000005513unm:VoluntaryBenefitsMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-04-012019-06-300000005513unm:VoluntaryBenefitsMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-01-012020-06-300000005513unm:VoluntaryBenefitsMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-01-012019-06-300000005513unm:DentalandVisionMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-04-012020-06-300000005513unm:DentalandVisionMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-04-012019-06-300000005513unm:DentalandVisionMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-01-012020-06-300000005513unm:DentalandVisionMemberus-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-01-012019-06-300000005513us-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-04-012020-06-300000005513us-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-04-012019-06-300000005513us-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-01-012020-06-300000005513us-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-01-012019-06-300000005513unm:UnumInternationalMemberunm:GroupLongTermDisabilityMemberus-gaap:OperatingSegmentsMember2020-04-012020-06-300000005513unm:UnumInternationalMemberunm:GroupLongTermDisabilityMemberus-gaap:OperatingSegmentsMember2019-04-012019-06-300000005513unm:UnumInternationalMemberunm:GroupLongTermDisabilityMemberus-gaap:OperatingSegmentsMember2020-01-012020-06-300000005513unm:UnumInternationalMemberunm:GroupLongTermDisabilityMemberus-gaap:OperatingSegmentsMember2019-01-012019-06-300000005513unm:UnumInternationalMemberunm:GroupLifeMemberus-gaap:OperatingSegmentsMember2020-04-012020-06-300000005513unm:UnumInternationalMemberunm:GroupLifeMemberus-gaap:OperatingSegmentsMember2019-04-012019-06-300000005513unm:UnumInternationalMemberunm:GroupLifeMemberus-gaap:OperatingSegmentsMember2020-01-012020-06-300000005513unm:UnumInternationalMemberunm:GroupLifeMemberus-gaap:OperatingSegmentsMember2019-01-012019-06-300000005513unm:SupplementalandVoluntaryInsuranceMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2020-04-012020-06-300000005513unm:SupplementalandVoluntaryInsuranceMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2019-04-012019-06-300000005513unm:SupplementalandVoluntaryInsuranceMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2020-01-012020-06-300000005513unm:SupplementalandVoluntaryInsuranceMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2019-01-012019-06-300000005513unm:UnumPolandMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2020-04-012020-06-300000005513unm:UnumPolandMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2019-04-012019-06-300000005513unm:UnumPolandMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2020-01-012020-06-300000005513unm:UnumPolandMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2019-01-012019-06-300000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2020-04-012020-06-300000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2019-04-012019-06-300000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2020-01-012020-06-300000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2019-01-012019-06-300000005513us-gaap:AccidentAndHealthInsuranceSegmentMemberus-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2020-04-012020-06-300000005513us-gaap:AccidentAndHealthInsuranceSegmentMemberus-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2019-04-012019-06-300000005513us-gaap:AccidentAndHealthInsuranceSegmentMemberus-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2020-01-012020-06-300000005513us-gaap:AccidentAndHealthInsuranceSegmentMemberus-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2019-01-012019-06-300000005513us-gaap:OperatingSegmentsMemberus-gaap:LifeInsuranceSegmentMemberunm:ColonialLifeMember2020-04-012020-06-300000005513us-gaap:OperatingSegmentsMemberus-gaap:LifeInsuranceSegmentMemberunm:ColonialLifeMember2019-04-012019-06-300000005513us-gaap:OperatingSegmentsMemberus-gaap:LifeInsuranceSegmentMemberunm:ColonialLifeMember2020-01-012020-06-300000005513us-gaap:OperatingSegmentsMemberus-gaap:LifeInsuranceSegmentMemberunm:ColonialLifeMember2019-01-012019-06-300000005513unm:CancerAndCriticalIllnessColonialMemberus-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2020-04-012020-06-300000005513unm:CancerAndCriticalIllnessColonialMemberus-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2019-04-012019-06-300000005513unm:CancerAndCriticalIllnessColonialMemberus-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2020-01-012020-06-300000005513unm:CancerAndCriticalIllnessColonialMemberus-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2019-01-012019-06-300000005513us-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2020-04-012020-06-300000005513us-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2019-04-012019-06-300000005513us-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2020-01-012020-06-300000005513us-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2019-01-012019-06-300000005513us-gaap:OperatingSegmentsMemberunm:ClosedBlockMemberunm:LongTermCareMember2020-04-012020-06-300000005513us-gaap:OperatingSegmentsMemberunm:ClosedBlockMemberunm:LongTermCareMember2019-04-012019-06-300000005513us-gaap:OperatingSegmentsMemberunm:ClosedBlockMemberunm:LongTermCareMember2020-01-012020-06-300000005513us-gaap:OperatingSegmentsMemberunm:ClosedBlockMemberunm:LongTermCareMember2019-01-012019-06-300000005513unm:IndividualDisabilityInsuranceMemberus-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2020-04-012020-06-300000005513unm:IndividualDisabilityInsuranceMemberus-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2019-04-012019-06-300000005513unm:IndividualDisabilityInsuranceMemberus-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2020-01-012020-06-300000005513unm:IndividualDisabilityInsuranceMemberus-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2019-01-012019-06-300000005513us-gaap:OtherInsuranceProductLineMemberus-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2020-04-012020-06-300000005513us-gaap:OtherInsuranceProductLineMemberus-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2019-04-012019-06-300000005513us-gaap:OtherInsuranceProductLineMemberus-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2020-01-012020-06-300000005513us-gaap:OtherInsuranceProductLineMemberus-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2019-01-012019-06-300000005513us-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2020-04-012020-06-300000005513us-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2019-04-012019-06-300000005513us-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2020-01-012020-06-300000005513us-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2019-01-012019-06-300000005513us-gaap:OperatingSegmentsMember2020-04-012020-06-300000005513us-gaap:OperatingSegmentsMember2019-04-012019-06-300000005513us-gaap:OperatingSegmentsMember2020-01-012020-06-300000005513us-gaap:OperatingSegmentsMember2019-01-012019-06-300000005513us-gaap:CorporateAndOtherMemberus-gaap:OperatingSegmentsMember2020-04-012020-06-300000005513us-gaap:CorporateAndOtherMemberus-gaap:OperatingSegmentsMember2019-04-012019-06-300000005513us-gaap:CorporateAndOtherMemberus-gaap:OperatingSegmentsMember2020-01-012020-06-300000005513us-gaap:CorporateAndOtherMemberus-gaap:OperatingSegmentsMember2019-01-012019-06-300000005513us-gaap:OperatingSegmentsMemberunm:UnumUsMember2020-06-300000005513us-gaap:OperatingSegmentsMemberunm:UnumUsMember2019-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2020-06-300000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2019-12-310000005513us-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2020-06-300000005513us-gaap:OperatingSegmentsMemberunm:ColonialLifeMember2019-12-310000005513us-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2020-06-300000005513us-gaap:OperatingSegmentsMemberunm:ClosedBlockMember2019-12-310000005513us-gaap:CorporateAndOtherMemberus-gaap:OperatingSegmentsMember2020-06-300000005513us-gaap:CorporateAndOtherMemberus-gaap:OperatingSegmentsMember2019-12-310000005513us-gaap:PensionPlansDefinedBenefitMembercountry:USunm:GroupAnnuityContactMember2020-01-012020-06-300000005513us-gaap:PensionPlansDefinedBenefitMembercountry:US2020-04-012020-06-300000005513us-gaap:PensionPlansDefinedBenefitMembercountry:US2019-04-012019-06-300000005513us-gaap:PensionPlansDefinedBenefitMembercountry:GB2020-04-012020-06-300000005513us-gaap:PensionPlansDefinedBenefitMembercountry:GB2019-04-012019-06-300000005513us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2020-04-012020-06-300000005513us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2019-04-012019-06-300000005513us-gaap:PensionPlansDefinedBenefitMembercountry:US2020-01-012020-06-300000005513us-gaap:PensionPlansDefinedBenefitMembercountry:US2019-01-012019-06-300000005513us-gaap:PensionPlansDefinedBenefitMembercountry:GB2020-01-012020-06-300000005513us-gaap:PensionPlansDefinedBenefitMembercountry:GB2019-01-012019-06-300000005513us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2020-01-012020-06-300000005513us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2019-01-012019-06-300000005513unm:RepurchaseProgramAuthorizedInMay2019Member2020-06-300000005513unm:RepurchaseProgramAuthorizedinMay2018Member2020-06-300000005513unm:OpenMarketRepurchaseMember2019-04-012019-06-300000005513unm:OpenMarketRepurchaseMember2019-01-012019-06-300000005513unm:NorthwindHoldingsLlcMember2020-01-012020-06-300000005513unm:A4500SeniorNotesDue2025Memberus-gaap:SeniorNotesMember2020-01-012020-06-300000005513unm:FiveYearUnsecuredRevolvingCreditFacilityMember2020-06-30

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D. C. 20549

FORM 10-Q

(Mark One)

☒ Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the quarterly period ended June 30, 2020

☐ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the transition period from to

Commission file number 001-11294

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes [X] No [ ]

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes [X] No [ ]

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and "emerging growth company" in Rule 12b-2 of the Exchange Act.