Securities - Schedule of Available for Sale Securities (Unrealized Loss Position) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Held-to-maturity securities:
Temporarily impaired securities, fair value, less than 12 months	$ 6,508	$ 13,776
Temporarily impaired securities, gross unrealized losses, less than 12 months	362	1,140
Temporarily impaired securities, fair value, 12 months or longer	39,577	32,405
Temporarily impaired securities, gross unrealized losses, 12 months or longer	6,484	5,900
Temporarily impaired securities, fair value	46,085	46,181
Temporarily impaired securities, gross unrealized losses	6,846	7,040
U.S. Treasury, agencies and corporations
Securities available for sale:
Fair value, less than 12 months	0	494
Gross unrealized losses, less than 12 months	0	48
Fair value, 12 months or longer	9,489	8,920
Gross unrealized losses, 12 months or longer	520	581
Fair value	9,489	9,414
Gross unrealized losses	520	629
Agency residential collateralized mortgage obligations
Securities available for sale:
Fair value, less than 12 months	92	3,114
Gross unrealized losses, less than 12 months	5	377
Fair value, 12 months or longer	15,523	13,317
Gross unrealized losses, 12 months or longer	3,686	3,370
Fair value	15,615	16,431
Gross unrealized losses	3,691	3,747
Held-to-maturity securities:
Fair value, less than 12 months	3,456	2,659
Gross unrealized losses, less than 12 months	150	178
Fair value, 12 months or longer	1,310	726
Gross unrealized losses, 12 months or longer	170	105
Fair value	4,766	3,385
Gross unrealized losses	320	283
Agency residential mortgage-backed securities
Held-to-maturity securities:
Fair value, less than 12 months	44
Gross unrealized losses, less than 12 months	2
Fair value, 12 months or longer	114
Gross unrealized losses, 12 months or longer	13
Fair value	158
Gross unrealized losses	15
Agency residential mortgage-backed securities \| Maximum
Held-to-maturity securities:
Gross unrealized losses	1	1
Agency residential mortgage-backed securities \| Mortgage-backed securities
Securities available for sale:
Fair value, less than 12 months	330	579
Gross unrealized losses, less than 12 months	16	31
Fair value, 12 months or longer	3,416	3,338
Gross unrealized losses, 12 months or longer	650	665
Fair value	3,746	3,917
Gross unrealized losses	666	696
Held-to-maturity securities:
Fair value, less than 12 months		165
Gross unrealized losses, less than 12 months		16
Fair value, 12 months or longer		0
Gross unrealized losses, 12 months or longer		0
Fair value		165
Gross unrealized losses		16
Agency commercial mortgage-backed securities
Held-to-maturity securities:
Fair value, less than 12 months	376	2,243
Gross unrealized losses, less than 12 months	47	208
Fair value, 12 months or longer	1,880	0
Gross unrealized losses, 12 months or longer	182	0
Fair value	2,256	2,243
Gross unrealized losses	229	208
Agency commercial mortgage-backed securities \| Mortgage-backed securities
Securities available for sale:
Fair value, less than 12 months	2,200	4,511
Gross unrealized losses, less than 12 months	142	282
Fair value, 12 months or longer	6,855	4,791
Gross unrealized losses, 12 months or longer	1,209	1,083
Fair value	9,055	9,302
Gross unrealized losses	1,351	1,365
Asset-backed securities
Held-to-maturity securities:
Fair value, less than 12 months	0	1
Gross unrealized losses, less than 12 months	0	0
Fair value, 12 months or longer	985	1,309
Gross unrealized losses, 12 months or longer	53	96
Fair value	985	1,310
Gross unrealized losses	53	96
Other securities
Held-to-maturity securities:
Fair value, less than 12 months	10	10
Gross unrealized losses, less than 12 months	0	0
Fair value, 12 months or longer	5	4
Gross unrealized losses, 12 months or longer	1	0
Fair value	15	14
Gross unrealized losses	$ 1	$ 0

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