Securities - Fair Value of Investments with Continuous Unrealized Loss Position (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	$ 66,340	$ 47,036
Less than 12 months, Unrealized losses	4,602	636
12 months or more, Fair value	16,151	4,661
12 months or more, Unrealized losses	2,519	158
Total, Fair value	82,491	51,697
Total, Unrealized losses	7,121	794
Debt securities, available-for-sale, unrealized loss position	82,491	51,697
Debt securities, available-for-sale, unrealized loss position, accumulated loss	7,121	794
AOCI, transfers from AFS to HTM Securities, gross unrealized losses, less than 12 months	126	47
AOCI, transfers from AFS to HTM Securities, gross unrealized losses, greater than 12 months	62	28
U.S. Treasury
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	22,678	16,855
Less than 12 months, Unrealized losses	1,942	235
12 months or more, Fair value	5,479	1,944
12 months or more, Unrealized losses	907	93
Total, Fair value	28,157	18,799
Total, Unrealized losses	2,849	328
Debt securities, available-for-sale, unrealized loss position	28,157	18,799
Debt securities, available-for-sale, unrealized loss position, accumulated loss	2,849	328
Sovereign debt/sovereign guaranteed
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	7,361	6,040
Less than 12 months, Unrealized losses	334	66
12 months or more, Fair value	1,738	58
12 months or more, Unrealized losses	240	1
Total, Fair value	9,099	6,098
Total, Unrealized losses	574	67
Debt securities, available-for-sale, unrealized loss position	9,099	6,098
Debt securities, available-for-sale, unrealized loss position, accumulated loss	574	67
Agency residential mortgage-backed securities (“RMBS”)
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	7,912	4,089
Less than 12 months, Unrealized losses	416	44
12 months or more, Fair value	384	457
12 months or more, Unrealized losses	70	29
Total, Fair value	8,296	4,546
Total, Unrealized losses	486	73
Debt securities, available-for-sale, unrealized loss position	8,296	4,546
Debt securities, available-for-sale, unrealized loss position, accumulated loss	486	73
Agency commercial mortgage-backed securities (“MBS”)
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	6,602	2,233
Less than 12 months, Unrealized losses	518	39
12 months or more, Fair value	1,410	585
12 months or more, Unrealized losses	200	3
Total, Fair value	8,012	2,818
Total, Unrealized losses	718	42
Debt securities, available-for-sale, unrealized loss position	8,012	2,818
Debt securities, available-for-sale, unrealized loss position, accumulated loss	718	42
Supranational
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	4,590	3,093
Less than 12 months, Unrealized losses	214	44
12 months or more, Fair value	1,491	305
12 months or more, Unrealized losses	212	6
Total, Fair value	6,081	3,398
Total, Unrealized losses	426	50
Debt securities, available-for-sale, unrealized loss position	6,081	3,398
Debt securities, available-for-sale, unrealized loss position, accumulated loss	426	50
Collateralized loan obligations (“CLOs”)
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	4,815	1,808
Less than 12 months, Unrealized losses	164	3
12 months or more, Fair value	324	318
12 months or more, Unrealized losses	15	2
Total, Fair value	5,139	2,126
Total, Unrealized losses	179	5
Debt securities, available-for-sale, unrealized loss position	5,139	2,126
Debt securities, available-for-sale, unrealized loss position, accumulated loss	179	5
Foreign covered bonds
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	3,657	2,694
Less than 12 months, Unrealized losses	166	23
12 months or more, Fair value	945	0
12 months or more, Unrealized losses	102	0
Total, Fair value	4,602	2,694
Total, Unrealized losses	268	23
Debt securities, available-for-sale, unrealized loss position	4,602	2,694
Debt securities, available-for-sale, unrealized loss position, accumulated loss	268	23
Non-agency commercial MBS
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	2,249	947
Less than 12 months, Unrealized losses	259	16
12 months or more, Fair value	594	222
12 months or more, Unrealized losses	118	7
Total, Fair value	2,843	1,169
Total, Unrealized losses	377	23
Debt securities, available-for-sale, unrealized loss position	2,843	1,169
Debt securities, available-for-sale, unrealized loss position, accumulated loss	377	23
Foreign government agencies
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	1,700	1,446
Less than 12 months, Unrealized losses	68	17
12 months or more, Fair value	615	15
12 months or more, Unrealized losses	66	0
Total, Fair value	2,315	1,461
Total, Unrealized losses	134	17
Debt securities, available-for-sale, unrealized loss position	2,315	1,461
Debt securities, available-for-sale, unrealized loss position, accumulated loss	134	17
Non-agency RMBS
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	1,058	1,573
Less than 12 months, Unrealized losses	82	20
12 months or more, Fair value	804	345
12 months or more, Unrealized losses	131	5
Total, Fair value	1,862	1,918
Total, Unrealized losses	213	25
Debt securities, available-for-sale, unrealized loss position	1,862	1,918
Debt securities, available-for-sale, unrealized loss position, accumulated loss	213	25
State and political subdivisions
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	757	1,848
Less than 12 months, Unrealized losses	128	40
12 months or more, Fair value	991	13
12 months or more, Unrealized losses	193	0
Total, Fair value	1,748	1,861
Total, Unrealized losses	321	40
Debt securities, available-for-sale, unrealized loss position	1,748	1,861
Debt securities, available-for-sale, unrealized loss position, accumulated loss	321	40
U.S. government agencies
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	1,515	1,780
Less than 12 months, Unrealized losses	197	27
12 months or more, Fair value	206	0
12 months or more, Unrealized losses	38	0
Total, Fair value	1,721	1,780
Total, Unrealized losses	235	27
Debt securities, available-for-sale, unrealized loss position	1,721	1,780
Debt securities, available-for-sale, unrealized loss position, accumulated loss	235	27
Other asset-backed securities (“ABS”)
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	925	1,383
Less than 12 months, Unrealized losses	75	20
12 months or more, Fair value	505	201
12 months or more, Unrealized losses	54	2
Total, Fair value	1,430	1,584
Total, Unrealized losses	129	22
Debt securities, available-for-sale, unrealized loss position	1,430	1,584
Debt securities, available-for-sale, unrealized loss position, accumulated loss	129	22
Corporate bonds
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, Fair value	521	1,247
Less than 12 months, Unrealized losses	39	42
12 months or more, Fair value	665	198
12 months or more, Unrealized losses	173	10
Total, Fair value	1,186	1,445
Total, Unrealized losses	212	52
Debt securities, available-for-sale, unrealized loss position	1,186	1,445
Debt securities, available-for-sale, unrealized loss position, accumulated loss	$ 212	$ 52