XML 53 R83.htm IDEA: XBRL DOCUMENT v2.4.1.9
Condensed Consolidating Financial Information (Details 3) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Operating activities    
Net cash provided by (used in) operating activities $ 630.9us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations $ 591.3us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
Investing activities    
Available-for-sale securities: Purchases (2,220.1)us-gaap_PaymentsToAcquireAvailableForSaleSecurities (2,659.5)us-gaap_PaymentsToAcquireAvailableForSaleSecurities
Available-for-sale securities: Sales 567.5us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities 475.3us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities
Available-for-sale securities: Maturities 1,694.3us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities 1,495.9us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities
Mortgage loans acquired or originated (511.3)us-gaap_PaymentsToAcquireMortgageNotesReceivable (319.3)us-gaap_PaymentsToAcquireMortgageNotesReceivable
Mortgage loans sold or repaid 408.9us-gaap_ProceedsFromSaleAndCollectionOfMortgageNotesReceivable 335.1us-gaap_ProceedsFromSaleAndCollectionOfMortgageNotesReceivable
Real estate acquired (87.9)us-gaap_PaymentsToAcquireRealEstateHeldForInvestment (182.2)us-gaap_PaymentsToAcquireRealEstateHeldForInvestment
Net (purchases) sales of property and equipment (32.8)pfg_PaymentsToAcquirePropertyPlantAndEquipmentNet (49.8)pfg_PaymentsToAcquirePropertyPlantAndEquipmentNet
Net change in other investments (48.1)us-gaap_PaymentsForProceedsFromOtherInvestingActivities 69.2us-gaap_PaymentsForProceedsFromOtherInvestingActivities
Net cash provided by (used in) investing activities (229.5)us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations (835.3)us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
Financing activities    
Issuance of common stock 17.9us-gaap_ProceedsFromIssuanceOfCommonStock 16.1us-gaap_ProceedsFromIssuanceOfCommonStock
Acquisition of treasury stock (75.4)us-gaap_PaymentsForRepurchaseOfCommonStock (89.0)us-gaap_PaymentsForRepurchaseOfCommonStock
Proceeds from financing element derivatives 0.2us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities 14.4us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities
Payments for financing element derivatives (19.3)us-gaap_PaymentsForDerivativeInstrumentFinancingActivities (12.7)us-gaap_PaymentsForDerivativeInstrumentFinancingActivities
Excess tax benefits from share-based payment arrangements 13.0us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities 4.9us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities
Purchase of subsidiary shares from noncontrolling interest (8.7)us-gaap_PaymentsToMinorityShareholders (25.3)us-gaap_PaymentsToMinorityShareholders
Dividends to common stockholders (106.3)us-gaap_PaymentsOfDividendsCommonStock (82.7)us-gaap_PaymentsOfDividendsCommonStock
Dividends to preferred stockholders (8.2)us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock  
Issuance of long-term debt 3.1us-gaap_ProceedsFromIssuanceOfLongTermDebt 14.0us-gaap_ProceedsFromIssuanceOfLongTermDebt
Principal repayments of long-term debt (19.8)us-gaap_RepaymentsOfLongTermDebt (100.1)us-gaap_RepaymentsOfLongTermDebt
Net proceeds from (repayments of) short-term borrowings (0.1)us-gaap_ProceedsFromRepaymentsOfShortTermDebt (0.3)us-gaap_ProceedsFromRepaymentsOfShortTermDebt
Investment contract deposits 1,277.8us-gaap_AdditionsToContractHoldersFunds 1,319.7us-gaap_AdditionsToContractHoldersFunds
Investment contract withdrawals (1,871.9)us-gaap_WithdrawalFromContractHoldersFunds (1,751.5)us-gaap_WithdrawalFromContractHoldersFunds
Net increase (decrease) in banking operation deposits (13.5)us-gaap_IncreaseDecreaseInDeposits (39.1)us-gaap_IncreaseDecreaseInDeposits
Other (2.1)us-gaap_ProceedsFromPaymentsForOtherFinancingActivities (3.1)us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
Net cash provided by (used in) financing activities (813.3)us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations (734.7)us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
Net increase (decrease) in cash and cash equivalents (411.9)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease (978.7)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
Cash and cash equivalents at beginning of period 1,863.9us-gaap_CashAndCashEquivalentsAtCarryingValue 2,371.8us-gaap_CashAndCashEquivalentsAtCarryingValue
Cash and cash equivalents at end of period 1,452.0us-gaap_CashAndCashEquivalentsAtCarryingValue 1,393.1us-gaap_CashAndCashEquivalentsAtCarryingValue
Principal Financial Group, Inc. Parent Only    
Operating activities    
Net cash provided by (used in) operating activities 11.7us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
1.1us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
Investing activities    
Dividends and returns of capital received from (contributions to) unconsolidated entities 225.4pfg_DividendsReceivedFromContributionsToUnconsolidatedEntities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
116.5pfg_DividendsReceivedFromContributionsToUnconsolidatedEntities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
Net change in other investments (2.5)us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
(2.2)us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
Net cash provided by (used in) investing activities 222.9us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
114.3us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
Financing activities    
Issuance of common stock 17.9us-gaap_ProceedsFromIssuanceOfCommonStock
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
16.1us-gaap_ProceedsFromIssuanceOfCommonStock
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
Acquisition of treasury stock (75.4)us-gaap_PaymentsForRepurchaseOfCommonStock
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
(89.0)us-gaap_PaymentsForRepurchaseOfCommonStock
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
Excess tax benefits from share-based payment arrangements 0.4us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
0.1us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
Dividends to common stockholders (106.3)us-gaap_PaymentsOfDividendsCommonStock
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
(82.7)us-gaap_PaymentsOfDividendsCommonStock
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
Dividends to preferred stockholders (8.2)us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
 
Net cash provided by (used in) financing activities (171.6)us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
(155.5)us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
Net increase (decrease) in cash and cash equivalents 63.0us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
(40.1)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
Cash and cash equivalents at beginning of period 412.4us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
131.5us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
Cash and cash equivalents at end of period 475.4us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
91.4us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= us-gaap_ParentCompanyMember
Principal Life Insurance Company Only    
Operating activities    
Net cash provided by (used in) operating activities 594.0us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
301.4us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Investing activities    
Available-for-sale securities: Purchases (1,976.7)us-gaap_PaymentsToAcquireAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
(2,430.9)us-gaap_PaymentsToAcquireAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Available-for-sale securities: Sales 463.4us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
428.7us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Available-for-sale securities: Maturities 1,499.5us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
1,346.1us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Mortgage loans acquired or originated (526.9)us-gaap_PaymentsToAcquireMortgageNotesReceivable
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
(278.0)us-gaap_PaymentsToAcquireMortgageNotesReceivable
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Mortgage loans sold or repaid 374.4us-gaap_ProceedsFromSaleAndCollectionOfMortgageNotesReceivable
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
283.5us-gaap_ProceedsFromSaleAndCollectionOfMortgageNotesReceivable
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Real estate acquired (0.3)us-gaap_PaymentsToAcquireRealEstateHeldForInvestment
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
 
Net (purchases) sales of property and equipment (26.7)pfg_PaymentsToAcquirePropertyPlantAndEquipmentNet
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
(30.6)pfg_PaymentsToAcquirePropertyPlantAndEquipmentNet
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Dividends and returns of capital received from (contributions to) unconsolidated entities (2.8)pfg_DividendsReceivedFromContributionsToUnconsolidatedEntities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
66.6pfg_DividendsReceivedFromContributionsToUnconsolidatedEntities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Net change in other investments (79.8)us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
(2.7)us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Net cash provided by (used in) investing activities (275.9)us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
(617.3)us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Financing activities    
Proceeds from financing element derivatives 0.2us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
14.4us-gaap_ProceedsFromDerivativeInstrumentFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Payments for financing element derivatives (19.3)us-gaap_PaymentsForDerivativeInstrumentFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
(12.7)us-gaap_PaymentsForDerivativeInstrumentFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Excess tax benefits from share-based payment arrangements 4.7us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
2.0us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Principal repayments of long-term debt   (100.0)us-gaap_RepaymentsOfLongTermDebt
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Capital received from (dividends and capital paid to) parent (125.4)pfg_CapitalReceivedFromDividendsPaidToParent
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
(116.5)pfg_CapitalReceivedFromDividendsPaidToParent
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Investment contract deposits 1,204.7us-gaap_AdditionsToContractHoldersFunds
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
1,319.7us-gaap_AdditionsToContractHoldersFunds
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Investment contract withdrawals (1,869.7)us-gaap_WithdrawalFromContractHoldersFunds
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
(1,751.5)us-gaap_WithdrawalFromContractHoldersFunds
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Other (2.1)us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
(3.3)us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Net cash provided by (used in) financing activities (806.9)us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
(647.9)us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Net increase (decrease) in cash and cash equivalents (488.8)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
(963.8)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Cash and cash equivalents at beginning of period 602.7us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
1,332.2us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Cash and cash equivalents at end of period 113.9us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
368.4us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
Principal Financial Services, Inc. and Other Subsidiaries Combined    
Operating activities    
Net cash provided by (used in) operating activities (141.8)us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
116.0us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Investing activities    
Available-for-sale securities: Purchases (243.4)us-gaap_PaymentsToAcquireAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
(228.6)us-gaap_PaymentsToAcquireAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Available-for-sale securities: Sales 109.9us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
46.6us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Available-for-sale securities: Maturities 194.8us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
149.8us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Mortgage loans acquired or originated (63.6)us-gaap_PaymentsToAcquireMortgageNotesReceivable
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
(41.3)us-gaap_PaymentsToAcquireMortgageNotesReceivable
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Mortgage loans sold or repaid 61.5us-gaap_ProceedsFromSaleAndCollectionOfMortgageNotesReceivable
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
51.6us-gaap_ProceedsFromSaleAndCollectionOfMortgageNotesReceivable
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Real estate acquired (87.6)us-gaap_PaymentsToAcquireRealEstateHeldForInvestment
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
(182.2)us-gaap_PaymentsToAcquireRealEstateHeldForInvestment
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Net (purchases) sales of property and equipment (6.1)pfg_PaymentsToAcquirePropertyPlantAndEquipmentNet
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
(19.2)pfg_PaymentsToAcquirePropertyPlantAndEquipmentNet
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Dividends and returns of capital received from (contributions to) unconsolidated entities 125.4pfg_DividendsReceivedFromContributionsToUnconsolidatedEntities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
116.5pfg_DividendsReceivedFromContributionsToUnconsolidatedEntities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Net change in other investments (141.5)us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
64.2us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Net cash provided by (used in) investing activities (50.6)us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
(42.6)us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Financing activities    
Excess tax benefits from share-based payment arrangements 7.9us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
2.8us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Purchase of subsidiary shares from noncontrolling interest (8.7)us-gaap_PaymentsToMinorityShareholders
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
(25.3)us-gaap_PaymentsToMinorityShareholders
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Issuance of long-term debt 70.3us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
38.2us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Principal repayments of long-term debt (47.8)us-gaap_RepaymentsOfLongTermDebt
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
(0.1)us-gaap_RepaymentsOfLongTermDebt
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Net proceeds from (repayments of) short-term borrowings (0.1)us-gaap_ProceedsFromRepaymentsOfShortTermDebt
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
(0.3)us-gaap_ProceedsFromRepaymentsOfShortTermDebt
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Capital received from (dividends and capital paid to) parent (222.6)pfg_CapitalReceivedFromDividendsPaidToParent
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
(183.1)pfg_CapitalReceivedFromDividendsPaidToParent
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Investment contract deposits 73.1us-gaap_AdditionsToContractHoldersFunds
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
 
Investment contract withdrawals (2.2)us-gaap_WithdrawalFromContractHoldersFunds
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
 
Net increase (decrease) in banking operation deposits (13.5)us-gaap_IncreaseDecreaseInDeposits
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
(39.1)us-gaap_IncreaseDecreaseInDeposits
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Other   0.2us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Net cash provided by (used in) financing activities (143.6)us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
(206.7)us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Net increase (decrease) in cash and cash equivalents (336.0)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
(133.3)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Cash and cash equivalents at beginning of period 1,253.6us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
894.5us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Cash and cash equivalents at end of period 917.6us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
761.2us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_SubsidiariesPrincipalFinancialServicesAndOtherMember
Eliminations, Notes Guarantor    
Operating activities    
Net cash provided by (used in) operating activities 167.0us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
172.8us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
Investing activities    
Available-for-sale securities: Sales (5.8)us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
 
Mortgage loans acquired or originated 79.2us-gaap_PaymentsToAcquireMortgageNotesReceivable
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
 
Mortgage loans sold or repaid (27.0)us-gaap_ProceedsFromSaleAndCollectionOfMortgageNotesReceivable
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
 
Dividends and returns of capital received from (contributions to) unconsolidated entities (348.0)pfg_DividendsReceivedFromContributionsToUnconsolidatedEntities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
(299.6)pfg_DividendsReceivedFromContributionsToUnconsolidatedEntities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
Net change in other investments 175.7us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
9.9us-gaap_PaymentsForProceedsFromOtherInvestingActivities
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
Net cash provided by (used in) investing activities (125.9)us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
(289.7)us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
Financing activities    
Issuance of long-term debt (67.2)us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
(24.2)us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
Principal repayments of long-term debt 28.0us-gaap_RepaymentsOfLongTermDebt
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
 
Capital received from (dividends and capital paid to) parent 348.0pfg_CapitalReceivedFromDividendsPaidToParent
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
299.6pfg_CapitalReceivedFromDividendsPaidToParent
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
Net cash provided by (used in) financing activities 308.8us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
275.4us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
Net increase (decrease) in cash and cash equivalents 349.9us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
158.5us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
Cash and cash equivalents at beginning of period (404.8)us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
13.6us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
Cash and cash equivalents at end of period $ (54.9)us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember
$ 172.1us-gaap_CashAndCashEquivalentsAtCarryingValue
/ pfg_ParentAndSubsidiariesNotesGuarantorAxis
= pfg_ConsolidationEliminationsAndOtherNotesGuarantorMember