Investment Securities - Held-to-Maturity Securities (Details) - USD ($) $ in Millions		Jun. 30, 2025	Dec. 31, 2024
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	[1]	$ 77,879	$ 78,634
Unrealized Gains		52	6
Unrealized Losses		(10,899)	(12,365)
Fair Value		67,032	66,275
U.S. Treasury and agencies
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost		647	1,296
Unrealized Gains		0	0
Unrealized Losses		(9)	(21)
Fair Value		638	1,275
Residential mortgage-backed securities | Agency
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost		75,272	75,392
Unrealized Gains		32	3
Unrealized Losses		(10,887)	(12,317)
Fair Value		64,417	63,078
Commercial mortgage-backed securities | Agency
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost		1,700	1,702
Unrealized Gains		16	0
Unrealized Losses		(3)	(27)
Fair Value		1,713	1,675
Other
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost		260	244
Unrealized Gains		4	3
Unrealized Losses		0	0
Fair Value		$ 264	$ 247

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