Guaranteed Benefit Features (Narrative) (Details)	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Guaranteed Benefit Features [Abstract]
Percent of permanent life insurance in force	35.00%		35.00%
Percent of permanent life insurance sales	35.00%	26.00%

Universal life and variable universal life products with secondary guarantees in force as a percentage of total permanent life insurance in force.

No definition available.

Name:	lnc_PercentOfPermanentLifeInsuranceInForce
Namespace Prefix:	lnc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant