Future Contract Benefits - Summary of Discounted and Undiscounted Expected Future Benefit Payments (Group Protection) (Details) - Group Protection - USD ($) $ in Millions	Mar. 31, 2025	Mar. 31, 2024
Undiscounted
Expected future benefit payments	$ 7,413	$ 7,296
Discounted
Expected future benefit payments	$ 5,712	$ 5,640

Liability For Future Policy Benefit, Discounted, Befiore Reinsurance

No definition available.

Name:	lnc_LiabilityForFuturePolicyBenefitDiscountedBefioreReinsuranceAbstract
Namespace Prefix:	lnc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Liability for future policy benefit, expected future policy benefit, discounted, before reinsurance.

+ References

No definition available.

+ Details

Name:	lnc_LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitDiscountedBeforeReinsurance
Namespace Prefix:	lnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Liability For Future Policy Benefit, Undiscounted, Befiore Reinsurance

+ References

No definition available.

+ Details

Name:	lnc_LiabilityForFuturePolicyBenefitUndiscountedBefioreReinsuranceAbstract
Namespace Prefix:	lnc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before effect of reinsurance, of undiscounted balance for expected future policy benefit and expense component of liability for future policy benefit.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480081/944-40-50-6

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 29E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480046/944-40-55-29E

+ Details

Name:	us-gaap_LiabilityForFuturePolicyBenefitExpectedFuturePolicyBenefitUndiscountedBeforeReinsurance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=lnc_GroupProtectionSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: