Other Assets (Summary of Equity Securities without Readily Determinable Fair Value) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Other Assets [Abstract]
FHLB stock	$ 548,000,000		$ 548,000,000		$ 289,000,000
FRB stock	449,000,000		449,000,000		449,000,000
Equity securities without a readily determinable fair value
Cost basis at acquisition	84,000,000		84,000,000		89,000,000
Upward adjustments	177,000,000		177,000,000		183,000,000
Downward adjustments (including impairment)	(7,000,000)		(7,000,000)		(12,000,000)
Carrying amount, equity securities without a readily determinable fair value	254,000,000		254,000,000		260,000,000
Nonmarketable equity investments	1,251,000,000		1,251,000,000		$ 998,000,000
Upward adjustments	0	$ 81,000,000	1,000,000	$ 81,000,000
Downward adjustments (including impairment)	0	(1,000,000)	(3,000,000)	(1,000,000)
Impairment of FHLB and FRB stock	0	0	0	0
Gain on nonmarketable equity investments, net	$ 3,000,000	$ 99,000,000	$ 2,000,000	$ 103,000,000