Derivative Instruments (Effects Of Qualifying And Non-Qualifying Hedges) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Realized Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Line Items in which the Effects of Fair Value or Cash Flow Hedges are Recorded	$ (24)	$ (362)
Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Line Items in which the Effects of Fair Value or Cash Flow Hedges are Recorded	1,375	1,251
Interest and Debt Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Line Items in which the Effects of Fair Value or Cash Flow Hedges are Recorded	68	71
Interest Rate Contracts [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member] \| Realized Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Non-Qualifying Hedges Gain (Loss)	2,150	357
Interest Rate Contracts [Member] \| Cash Flow Hedges [Member] \| Designated as Hedging Instrument [Member] \| Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain or (loss) reclassified from AOCI into income		1
Interest Rate Contracts [Member] \| Cash Flow Hedges [Member] \| Designated as Hedging Instrument [Member] \| Interest and Debt Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain or (loss) reclassified from AOCI into income	(3)	(1)
Interest Rate Contracts [Member] \| Fair Value Hedges [Member] \| Designated as Hedging Instrument [Member] \| Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedged items	127	24
Derivatives designated as hedging instruments	(127)	(24)
Interest Rate Contracts [Member] \| Fair Value Hedges [Member] \| Designated as Hedging Instrument [Member] \| Interest and Debt Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedged items	82	(34)
Derivatives designated as hedging instruments	(82)	34
Foreign currency contracts [Member] \| Cash Flow Hedges [Member] \| Designated as Hedging Instrument [Member] \| Realized Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain or (loss) reclassified from AOCI into income	1	1
Foreign currency contracts [Member] \| Cash Flow Hedges [Member] \| Designated as Hedging Instrument [Member] \| Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain or (loss) reclassified from AOCI into income	11	7
Equity market contracts [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member] \| Realized Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Non-Qualifying Hedges Gain (Loss)	1,070	(458)
Credit contracts [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member] \| Realized Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Non-Qualifying Hedges Gain (Loss)	(4)
Embedded derivatives - GLB [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member] \| Realized Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Non-Qualifying Hedges Gain (Loss)	(4,369)	286
Reinsurance Related [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member] \| Realized Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Non-Qualifying Hedges Gain (Loss)	463	(174)
Indexed Annuity And IUL Contracts [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member] \| Realized Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Non-Qualifying Hedges Gain (Loss)	$ 1,028	$ (239)

Amount of income (expense) line items in statement of financial position that hedges are recorded

No definition available.

Name:	lnc_AmountOfIncomeExpenseLineItemsInStatementOfFinancialPositionThatHedgesAreRecorded
Namespace Prefix:	lnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=109977999&loc=d3e76258-113986

+ Details

Name:	us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

+ References

+ Details

Name:	us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeInstrumentsGainLossLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624177-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959

+ Details

Name:	us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4CC
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998890-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959

+ Details

Name:	us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_IncomeStatementLocationAxis=lnc_RealizedGainLossMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=lnc_NetInvestmentIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_InterestExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_FairValueHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_EquityContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CreditRiskContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=lnc_GlbEmbeddedDerivativesReservesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=lnc_ReinsuranceRelatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=lnc_IndexedAnnuityContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: