Investment Securities - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Marketable Securities [Abstract]
Available-for-sale securities sold	$ 1,200,000,000
Losses on available-for-sale securities		$ 91,000,000	$ 0	$ 0
Available-for-sale, accrued interest, after allowance for credit loss	29,000,000	29,000,000	32,000,000
Transfers between available for sale and held to maturity debt securities		0	0	0
Held-to-maturity, accrued interest, after allowance for credit loss	3,000,000	3,000,000	3,000,000
Allowance for credit losses for HTM securities	0	0	0
Carrying amount of equity method investments without readily determinable fair value	$ 96,000,000	96,000,000	89,000,000
Downward valuation adjustment		0	6,000,000
Unrealized gains (losses) for equity investments with readily determinable fair value		11,000,000	$ 11,000,000	$ (11,000,000)
Upward valuation adjustment		$ 0