Derivative Instruments (Schedule Of Collateral Amounts With Rights To Reclaim Or Obligation To Return Cash) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Credit Derivatives [Line Items]
Collateral Posted by Counter-Party (Held by LNL)	$ 616	$ 701
Collateral Posted by LNL (Held by Counter-Party)	(66)	(506)
AA- [Member]
Credit Derivatives [Line Items]
Collateral Posted by Counter-Party (Held by LNL)	33	116
Collateral Posted by LNL (Held by Counter-Party)	(4)	(1)
A+ [Member]
Credit Derivatives [Line Items]
Collateral Posted by Counter-Party (Held by LNL)	296	178
Collateral Posted by LNL (Held by Counter-Party)	(26)	(453)
A [Member]
Credit Derivatives [Line Items]
Collateral Posted by Counter-Party (Held by LNL)	106	170
Collateral Posted by LNL (Held by Counter-Party)	(36)	(48)
A- [Member]
Credit Derivatives [Line Items]
Collateral Posted by Counter-Party (Held by LNL)	4	237
Collateral Posted by LNL (Held by Counter-Party)
BBB+ [Member]
Credit Derivatives [Line Items]
Collateral Posted by Counter-Party (Held by LNL)	177
Collateral Posted by LNL (Held by Counter-Party)		$ (4)