Stock-Based Incentive Compensation Plans (Total unrecognized compensation expense for all stock-based incentive compensation plans) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based compensation arrangement by share-based payment award [Line Items]
Unrecognized stock-based incentive compensation expense	$ 66	$ 73	$ 55
Stock Options [Member]
Share-based compensation arrangement by share-based payment award [Line Items]
Unrecognized stock-based incentive compensation expense	$ 9	$ 9	$ 9
Weighted average period (in years)	10 months 24 days	1 year 1 month 6 days	1 year 4 months 24 days
Performance Shares [Member]
Share-based compensation arrangement by share-based payment award [Line Items]
Unrecognized stock-based incentive compensation expense	$ 15	$ 14	$ 12
Weighted average period (in years)	1 year 3 months 18 days	10 months 24 days	1 year 2 months 12 days
SARs [Member]
Share-based compensation arrangement by share-based payment award [Line Items]
Unrecognized stock-based incentive compensation expense			$ 2
Weighted average period (in years)	3 years 4 months 24 days	2 years 8 months 12 days	3 years 2 months 12 days
RSUs [Member]
Share-based compensation arrangement by share-based payment award [Line Items]
Unrecognized stock-based incentive compensation expense	$ 42	$ 50	$ 32
Weighted average period (in years)	1 year 4 months 24 days	1 year 2 months 12 days	1 year 1 month 6 days

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=lnc_StockAppreciationRightsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=lnc_RestrictedStockUnitsAndNonVestedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: