Other Assets (Summary of Equity Securities without Readily Determinable Fair Value) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Other Assets [Abstract]
FRB stock	$ 396,000,000		$ 401,000,000
FHLB stock	324,000,000		318,000,000
Equity investments without a readily determinable fair value
Cost basis at acquisition	90,000,000		89,000,000
Upward adjustments	183,000,000		177,000,000
Downward adjustments (including impairment)	(160,000,000)		(143,000,000)
Carrying amount, equity investments without a readily determinable fair value	113,000,000		123,000,000
Nonmarketable equity investments	833,000,000		$ 842,000,000
Upward adjustments	5,000,000	$ 1,000,000
Downward adjustments (including impairment)	(17,000,000)	(2,000,000)
Impairment of FHLB and FRB stock	0	0
Loss on nonmarketable equity investments, net	$ (11,000,000)	$ (1,000,000)