Investment Securities - Held-to-Maturity Securities (Details) - USD ($) $ in Millions		Mar. 31, 2025	Dec. 31, 2024
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	[1]	$ 78,008	$ 78,634
Unrealized Gains		20	6
Unrealized Losses		(10,929)	(12,365)
Fair Value		67,099	66,275
U.S. Treasury and agencies
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost		1,297	1,296
Unrealized Gains		0	0
Unrealized Losses		(13)	(21)
Fair Value		1,284	1,275
Residential mortgage-backed securities | Agency
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost		74,773	75,392
Unrealized Gains		12	3
Unrealized Losses		(10,912)	(12,317)
Fair Value		63,873	63,078
Commercial mortgage-backed securities | Agency
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost		1,699	1,702
Unrealized Gains		5	0
Unrealized Losses		(4)	(27)
Fair Value		1,700	1,675
Other
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost		239	244
Unrealized Gains		3	3
Unrealized Losses		0	0
Fair Value		$ 242	$ 247

[1] Includes only collateral pledged by the Company where counterparties have the right to sell or pledge the collateral.