Shares and Stockholders' Equity (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Shares and Stockholders' Equity [Abstract]
Net Income Adjustment For Deferred Units of LNC Stock	$ 7	$ (2)	$ 6	$ (2)

Some participants in LNC's deferred compensation plans have selected LNC stock as the measure for the investment return attributable to deferred amounts. In the event that the effect of settling this obligation in LNC stock is more dilutive than settling it in cash, the EPS calculation is adjusted by adding these shares to the denominator. This amount is the change in the numerator for mark to market adjustments included in net income attributable to these deferred units of LNC stock.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration