Securities - Maturity Distribution and Yield of Investment Securities Portfolio (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Securities available-for-sale, Amount:
Within 1 year	$ 11,858
1-5 years	31,548
5-10 years	12,900
After 10 years	2,440
Available-for-sale, amount	$ 86,924	$ 101,839
Securities available-for-sale (Yield):
Within 1 year	1.75%
1-5 years	1.29%
5-10 years	1.41%
After 10 years	2.82%
Total	1.96%
Securities held-to-maturity, Amount:
Within 1 year	$ 1,642
1-5 years	11,157
5-10 years	3,710
After 10 years	269
Available-for-sale, amount	$ 57,257	56,866
Securities held-to-maturity (Yield):
Within 1 year	1.63%
1-5 years	1.23%
5-10 years	1.33%
After 10 years	1.98%
Total	2.03%
Total securities	$ 13,500
Total securities (percent)	1.73%
Total securities	$ 42,705
Total securities (percent)	1.27%
Total securities	$ 16,610
Total securities (percent)	1.40%
Total securities	$ 2,709
Total securities (percent)	2.75%
Total securities	$ 144,181
Total securities (percent)	1.99%
U.S. Treasury
Securities available-for-sale, Amount:
Within 1 year	$ 4,837
1-5 years	13,970
5-10 years	7,324
After 10 years	2,025
Available-for-sale, amount	$ 28,156	29,409
Securities available-for-sale (Yield):
Within 1 year	1.87%
1-5 years	0.93%
5-10 years	1.25%
After 10 years	2.92%
Total	1.32%
Securities held-to-maturity, Amount:
Within 1 year	$ 1,464
1-5 years	7,292
5-10 years	1,959
After 10 years	0
Available-for-sale, amount	$ 10,715	11,617
Securities held-to-maturity (Yield):
Within 1 year	1.79%
1-5 years	1.25%
5-10 years	1.16%
After 10 years	0.00%
Total	1.31%
Sovereign debt/sovereign guaranteed
Securities available-for-sale, Amount:
Within 1 year	$ 3,846
1-5 years	5,734
5-10 years	710
After 10 years	45
Available-for-sale, amount	$ 10,335
Securities available-for-sale (Yield):
Within 1 year	1.82%
1-5 years	1.13%
5-10 years	0.42%
After 10 years	2.65%
Total	1.32%
Securities held-to-maturity, Amount:
Within 1 year	$ 132
1-5 years	1,133
5-10 years	109
After 10 years	0
Available-for-sale, amount	$ 1,374
Securities held-to-maturity (Yield):
Within 1 year	0.16%
1-5 years	0.88%
5-10 years	0.95%
After 10 years	0.00%
Total	0.82%
Supranational
Securities available-for-sale, Amount:
Within 1 year	$ 1,303
1-5 years	4,745
5-10 years	1,536
After 10 years	15
Available-for-sale, amount	$ 7,599	7,573
Securities available-for-sale (Yield):
Within 1 year	1.21%
1-5 years	1.90%
5-10 years	2.26%
After 10 years	(0.09%)
Total	1.86%
Securities held-to-maturity, Amount:
Within 1 year	$ 45
1-5 years	362
5-10 years	0
After 10 years	0
Available-for-sale, amount	$ 407	54
Securities held-to-maturity (Yield):
Within 1 year	0.54%
1-5 years	1.01%
5-10 years	0.00%
After 10 years	0.00%
Total	0.96%
Foreign covered bonds
Securities available-for-sale, Amount:
Within 1 year	$ 1,131
1-5 years	3,619
5-10 years	530
After 10 years	0
Available-for-sale, amount	$ 5,280	6,238
Securities available-for-sale (Yield):
Within 1 year	1.66%
1-5 years	1.64%
5-10 years	0.18%
After 10 years	0.00%
Total	1.48%
Foreign government agencies
Securities available-for-sale, Amount:
Within 1 year	$ 540
1-5 years	1,743
5-10 years	32
After 10 years	0
Available-for-sale, amount	$ 2,315
Securities available-for-sale (Yield):
Within 1 year	1.03%
1-5 years	1.49%
5-10 years	0.16%
After 10 years	0.00%
Total	1.36%
Securities held-to-maturity, Amount:
Within 1 year	$ 0
1-5 years	60
5-10 years	0
After 10 years	0
Available-for-sale, amount	$ 60
Securities held-to-maturity (Yield):
Within 1 year	0.00%
1-5 years	0.79%
5-10 years	0.00%
After 10 years	0.00%
Total	0.79%
State and political subdivisions
Securities available-for-sale, Amount:
Within 1 year	$ 119
1-5 years	688
5-10 years	889
After 10 years	170
Available-for-sale, amount	$ 1,866	2,514
Securities available-for-sale (Yield):
Within 1 year	3.98%
1-5 years	1.50%
5-10 years	1.62%
After 10 years	2.41%
Total	1.79%
Securities held-to-maturity, Amount:
Within 1 year	$ 1
1-5 years	1
5-10 years	3
After 10 years	8
Available-for-sale, amount	$ 13	14
Securities held-to-maturity (Yield):
Within 1 year	5.48%
1-5 years	5.93%
5-10 years	4.65%
After 10 years	4.80%
Total	4.84%
U.S. government agencies
Securities available-for-sale, Amount:
Within 1 year	$ 0
1-5 years	711
5-10 years	1,122
After 10 years	164
Available-for-sale, amount	$ 1,997	2,536
Securities available-for-sale (Yield):
Within 1 year	0.00%
1-5 years	2.52%
5-10 years	2.41%
After 10 years	2.54%
Total	2.46%
Securities held-to-maturity, Amount:
Within 1 year	$ 0
1-5 years	2,309
5-10 years	1,639
After 10 years	261
Available-for-sale, amount	$ 4,209	2,998
Securities held-to-maturity (Yield):
Within 1 year	0.00%
1-5 years	1.40%
5-10 years	1.56%
After 10 years	1.90%
Total	1.49%
Corporate bonds
Securities available-for-sale, Amount:
Within 1 year	$ 82
1-5 years	338
5-10 years	757
After 10 years	20
Available-for-sale, amount	$ 1,197
Securities available-for-sale (Yield):
Within 1 year	2.40%
1-5 years	2.75%
5-10 years	1.61%
After 10 years	2.01%
Total	1.95%
Other debt securities
Securities available-for-sale, Amount:
Within 1 year	$ 0
1-5 years	0
5-10 years	0
After 10 years	1
Available-for-sale, amount	$ 1	1
Securities available-for-sale (Yield):
Within 1 year	0.00%
1-5 years	0.00%
5-10 years	0.00%
After 10 years	3.60%
Total	3.60%
Agency residential mortgage-backed securities (“RMBS”)
Securities available-for-sale, Amount:
Available-for-sale, amount	$ 8,365	14,530
Securities held-to-maturity, Amount:
Available-for-sale, amount	$ 35,349	36,167
Agency residential mortgage-backed securities (“RMBS”) | Mortgage-backed securities
Securities available-for-sale (Yield):
Total	3.10%
Securities held-to-maturity (Yield):
Total	2.29%
Non-agency RMBS
Securities available-for-sale, Amount:
Available-for-sale, amount	$ 2,113	2,748
Securities available-for-sale (Yield):
Total	3.32%
Securities held-to-maturity, Amount:
Available-for-sale, amount	$ 30	43
Securities held-to-maturity (Yield):
Total	2.22%
Agency commercial mortgage-backed securities (“MBS”)
Securities available-for-sale, Amount:
Available-for-sale, amount	$ 8,100	8,405
Securities available-for-sale (Yield):
Total	2.60%
Securities held-to-maturity, Amount:
Available-for-sale, amount	$ 4,117	4,068
Securities held-to-maturity (Yield):
Total	2.31%
Non-agency commercial MBS
Securities available-for-sale, Amount:
Available-for-sale, amount	$ 2,893	3,125
Securities available-for-sale (Yield):
Total	2.81%
Collateralized loan obligations (“CLOs”)
Securities available-for-sale, Amount:
Available-for-sale, amount	$ 5,242	4,439
Securities available-for-sale (Yield):
Total	3.72%
Securities held-to-maturity, Amount:
Available-for-sale, amount	$ 983	983
Securities held-to-maturity (Yield):
Total	3.80%
Other asset-backed securities (“ABS”)
Securities available-for-sale, Amount:
Available-for-sale, amount	$ 1,465	$ 2,190
Securities available-for-sale (Yield):
Total	1.94%