Investments (Schedule Of Increase (Decrease) In Payables For Collateral On Investments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Increase (decrease) in payables for collateral on investments
Collateral payable for derivative investments	$ 767	$ (85)	$ (112)
Securities pledged under securities lending agreements	26	(134)	5
Securities pledged under repurchase agreements	(152)	(379)	1
Investments pledged for FHLBI	(350)	1,030	(450)
Total increase (decrease) in payables for collateral on investments	$ 291	$ 432	$ (556)