Investments (Average Carrying Value On The Impaired Mortgage Loans On Real Estate) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Information about impaired mortgage loans on real estate
Average carrying value for impaired loans on real estate	$ 23	$ 24
Interest income recognized on impaired mortgage loans on real estate
Interest income collected on impaired mortgage loans on real estate

Interest income recognized on impaired mortgage loans on real estate.

No definition available.

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