Fair Value Measurements (Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Interest rate contracts
Balance at beginning of period			$ 29	$ 26	$ 39
Realized gains (losses) recorded in earnings	[1]		0	0	0
Unrealized gains (losses) recorded in earnings	[1]		(2)	0	(12)
Settlements			0	(26)	0
Balance at end of period		$ 0	27	0	27
Other financial derivative
Balance at beginning of period		(12)	(12)	(13)	(11)
Realized gains (losses) recorded in earnings	[1]	0	0	0	0
Unrealized gains (losses) recorded in earnings	[1]	0	0	1	(1)
Settlements		0	0	0	0
Balance at end of period		$ (12)	$ (12)	$ (12)	$ (12)

[1] Realized and unrealized gains and losses due to changes in fair value are recorded in other noninterest income on the Consolidated Statements of Comprehensive Income.