Other Assets - Schedule of Equity Securities without Readily Determinable Fair Value (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Other Assets [Abstract]
FRB stock	$ 440,000,000	$ 392,000,000
FHLB stock	258,000,000	392,000,000
Equity investments without a readily determinable fair value
Cost basis	74,000,000	74,000,000
Upward adjustments	53,000,000	51,000,000
Downward adjustments (including impairment)	(36,000,000)	(23,000,000)
Carrying amount, equity investments without a readily determinable fair value	91,000,000	102,000,000
Nonmarketable equity investments	789,000,000	886,000,000
Upward adjustments	2,000,000	8,000,000
Downward adjustments (including impairment)	(15,000,000)	(17,000,000)
Impairment of FHLB and FRB stock	$ 0	$ 0