Investments (Schedule Of Increase (Decrease) In Payables For Collateral On Investments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Increase (decrease) in payables for collateral on investments
Collateral payable for derivative investments	$ (128)	$ (129)	$ (493)
Securities pledged under securities lending agreements	(134)	6	(26)
Securities pledged under repurchase agreements	(380)	(5)	(138)
Investments pledged for FHLBI	1,030	(450)	995
Total increase (decrease) in payables for collateral on investments	$ 388	$ (578)	$ 338