Other Assets (Summary of Equity Securities without Readily Determinable Fair Value) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Other Assets [Abstract]
FRB stock	$ 415,000,000		$ 415,000,000		$ 401,000,000
FHLB stock	339,000,000		339,000,000		318,000,000
Equity investments without a readily determinable fair value
Cost basis at acquisition	92,000,000		92,000,000		89,000,000
Upward adjustments	184,000,000		184,000,000		177,000,000
Downward adjustments (including impairment)	(160,000,000)		(160,000,000)		(143,000,000)
Carrying amount, equity investments without a readily determinable fair value	116,000,000		116,000,000		123,000,000
Nonmarketable equity investments	870,000,000		870,000,000		$ 842,000,000
Upward adjustments	1,000,000	$ 0	7,000,000	$ 1,000,000
Downward adjustments (including impairment)	0	0	(17,000,000)	(3,000,000)
Impairment of FHLB and FRB stock	0	0	0	0
Gain (loss) on nonmarketable equity investments, net	$ 0	$ 3,000,000	$ (11,000,000)	$ 2,000,000