Securities - Schedule of Details of Securities (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
SECURITIES AVAILABLE FOR SALE
Amortized Cost	$ 44,136	$ 45,552
Gross Unrealized Gains	0	2
Gross Unrealized Losses	6,228	6,437
Fair Value	37,908	39,117
HELD-TO-MATURITY SECURITIES
Total	9,189	8,710
Gross Unrealized Gains	4	6
Gross Unrealized Losses	618	603
Fair Value	8,575	8,113
Debt securities, available for sale, accrued interest	63	67
Debt securities, held to maturity, accrued interest	27	88
U.S. Treasury, agencies and corporations
SECURITIES AVAILABLE FOR SALE
Amortized Cost	10,009	10,044
Gross Unrealized Gains	0	0
Gross Unrealized Losses	520	629
Fair Value	9,489	9,415
Agency residential collateralized mortgage obligations
SECURITIES AVAILABLE FOR SALE
Amortized Cost	19,306	20,180
Gross Unrealized Gains	0	0
Gross Unrealized Losses	3,691	3,747
Fair Value	15,615	16,433
HELD-TO-MATURITY SECURITIES
Total	5,431	4,586
Gross Unrealized Gains	3	5
Gross Unrealized Losses	320	283
Fair Value	5,114	4,308
Agency residential mortgage-backed securities \| Mortgage-backed securities
SECURITIES AVAILABLE FOR SALE
Amortized Cost	4,415	4,616
Gross Unrealized Gains	0	0
Gross Unrealized Losses	666	696
Fair Value	3,749	3,920
HELD-TO-MATURITY SECURITIES
Total	173	181
Gross Unrealized Gains	0	0
Gross Unrealized Losses	15	16
Fair Value	158	165
Agency commercial mortgage-backed securities \| Mortgage-backed securities
SECURITIES AVAILABLE FOR SALE
Amortized Cost	10,406	10,712
Gross Unrealized Gains	0	2
Gross Unrealized Losses	1,351	1,365
Fair Value	9,055	9,349
HELD-TO-MATURITY SECURITIES
Total	2,533	2,522
Gross Unrealized Gains	1	1
Gross Unrealized Losses	229	208
Fair Value	2,305	2,315
Asset-backed securities
HELD-TO-MATURITY SECURITIES
Total	1,037	1,407
Gross Unrealized Gains	0	0
Gross Unrealized Losses	53	96
Fair Value	984	1,311
Debt securities, held-to-maturity, purchase of senior notes	1,000	1,400
Other securities
SECURITIES AVAILABLE FOR SALE
Amortized Cost	0	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	0	0
HELD-TO-MATURITY SECURITIES
Total	15	14
Gross Unrealized Gains	0	0
Gross Unrealized Losses	1	0
Fair Value	$ 14	$ 14

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