Fair Value (Schedule Of Realize Gains (Losses) From Fair Value Changes) (Details) - Fair Value, Nonrecurring - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gains (losses) from fair value changes	$ 1	$ (1)	$ 1	$ (11)
Private equity investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gains (losses) from fair value changes	0	(1)	0	(1)
Collateral-dependent loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gains (losses) from fair value changes	1	0	1	(9)
Other real estate owned
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gains (losses) from fair value changes	$ 0	$ 0	$ 0	$ (1)