Investments (Schedule Of Increase (Decrease) In Payables For Collateral On Investments) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Increase (decrease) in payables for collateral on investments
Collateral payable for derivative investments	$ (399)	$ 41
Securities pledged under securities lending agreements	(105)	(16)
Securities pledged under repurchase agreements	(381)	(2)
Investments pledged for FHLBI	680	(50)
Total increase (decrease) in payables for collateral on investments	$ (205)	$ (27)