Securities - Schedule of Details of Securities (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
SECURITIES AVAILABLE FOR SALE
Amortized Cost	$ 41,396	$ 41,846
Gross Unrealized Gains	166	267
Gross Unrealized Losses	2,644	2,517
Fair Value	38,918	39,596
HELD-TO-MATURITY SECURITIES
Amortized Cost	9,116	8,622
Gross Unrealized Gains	10	21
Gross Unrealized Losses	384	330
Fair Value	8,742	8,313
Debt securities, available for sale, accrued interest	118	121
Debt securities, held to maturity, accrued interest	29	26
Basis adjustments for securities	38	99
U.S. Treasury, agencies and corporations
SECURITIES AVAILABLE FOR SALE
Amortized Cost	7,842	7,842
Gross Unrealized Gains	28	61
Gross Unrealized Losses	26	17
Fair Value	7,844	7,886
Agency residential collateralized mortgage obligations
SECURITIES AVAILABLE FOR SALE
Amortized Cost	10,003	10,269
Gross Unrealized Gains	6	4
Gross Unrealized Losses	1,760	1,708
Fair Value	8,249	8,565
HELD-TO-MATURITY SECURITIES
Amortized Cost	3,903	4,026
Gross Unrealized Gains	4	8
Gross Unrealized Losses	204	176
Fair Value	3,703	3,858
Agency residential mortgage-backed securities
SECURITIES AVAILABLE FOR SALE
Amortized Cost	19,308	19,451
Gross Unrealized Gains	132	201
Gross Unrealized Losses	507	457
Fair Value	18,933	19,195
HELD-TO-MATURITY SECURITIES
Amortized Cost	3,165	2,374
Gross Unrealized Gains	5	12
Gross Unrealized Losses	34	13
Fair Value	3,136	2,373
Agency commercial mortgage-backed securities
SECURITIES AVAILABLE FOR SALE
Amortized Cost	4,243	4,284
Gross Unrealized Gains	0	1
Gross Unrealized Losses	351	335
Fair Value	3,892	3,950
HELD-TO-MATURITY SECURITIES
Amortized Cost	1,984	2,121
Gross Unrealized Gains	1	1
Gross Unrealized Losses	145	139
Fair Value	1,840	1,983
Asset-backed securities
HELD-TO-MATURITY SECURITIES
Amortized Cost	44	77
Gross Unrealized Gains	0	0
Gross Unrealized Losses	1	2
Fair Value	43	75
Debt securities, held-to-maturity, purchase of senior notes	41	74
Other securities
HELD-TO-MATURITY SECURITIES
Amortized Cost	20	24
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 20	$ 24

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