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	$ 751	$ (128)	$ (129)
Securities pledged under securities lending agreements	26	(134)	6
Securities pledged under repurchase agreements	(150)	(380)	(5)
Investments pledged for FHLBI	(350)	1,030	(450)
Total increase (decrease) in payables for collateral on investments	$ 277	$ 388	$ (578)