Investments (Schedule Of Increase (Decrease) In Payables For Collateral On Investments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Increase (decrease) in payables for collateral on investments
Collateral payable held for derivative investments	$ (493)	$ (286)	$ 1,035
Securities pledged under securities lending agreements	(26)	38	20
Securities pledged under repurchase agreements	(138)	66	77
Securities pledged for TALF			(36)
Securities pledged for FHLBI	995	430	75
Total increase (decrease) in payables for collateral on investments	$ 338	$ 248	$ 1,171