Derivative And Credit-Related Financial Instruments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Cash received as collateral for derivative assets	$ 196		$ 196
Fair value of securities pledged as collateral for derivative assets	127		127
Cash posted as collateral for derivative liabilities	280		280
Net cash flow hedge gains included in interest and fees on loans	(2)	$ 24	45	$ 72
Allowance for credit losses on lending-related commitments	48		48		$ 30
Allowance for credit losses on lending-related commitments, amount related to unused commitments to extend credit	44		$ 44		27
Final year of expiration for outstanding letters of credit			2028
Risk participation agreements covering standby and commercial letters of credit	110		$ 110		98
Standby and commercial letters of credit	3,400		3,400		3,400
Carrying value of standby and commercial letters of credit included in accrued expenses and other liabilities	32		32		32
Deferred fees on standby and commercial letters of credit included in accrued expenses and other liabilities	28		28		29
Allowance for credit losses on lending-related commitments, amount related to standby and commercial letters of credit	4		4		3
Notional amount of derivative credit risk participation agreements	894		$ 894		1,100
Fair Value Amount of Derivative Credit Risk Participation Agreements					1
Maximum estimated exposure to credit risk participation agreements assuming 100% default					30
Weighted average remaining maturity of credit risk participation agreements, in years			3 years 10 months 24 days
Recurring
Total liabilities at fair value	2,230		$ 2,230		873
Level 3 | Recurring
Total liabilities at fair value	$ 12		$ 12		$ 13