AFS Debt Securities, Contractual Maturities (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Available-for-sale, at amortized cost, net	$ 124,906	$ 175,463
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year	3,293
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years	20,771
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years	36,720
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years	64,122
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]
Available-for-sale, fair value	115,835	177,244
Available-for-sale, fair value, remaining contractual maturity, due within one year	3,258
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years	20,265
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years	34,367
Available-for-sale, fair value, remaining contractual maturity, due after ten years	$ 57,945
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]
Available-for-sale, weighted average yield	2.42%
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year	2.10%
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years	0.73%
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years	1.94%
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years	3.25%
Securities of U.S. Treasury and federal agencies [Member]
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Available-for-sale, at amortized cost, net	$ 47,102	39,668
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year	2,039
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years	17,556
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years	25,968
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years	1,539
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]
Available-for-sale, fair value	44,730	39,661
Available-for-sale, fair value, remaining contractual maturity, due within one year	2,008
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years	17,082
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years	24,160
Available-for-sale, fair value, remaining contractual maturity, due after ten years	$ 1,480
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]
Available-for-sale, weighted average yield	1.06%
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year	1.44%
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years	0.39%
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years	1.46%
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years	1.44%
Non-U.S. government securities [Member]
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Available-for-sale, at amortized cost, net	$ 162	71
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year	1
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years	137
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years	24
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years	0
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]
Available-for-sale, fair value	162	71
Available-for-sale, fair value, remaining contractual maturity, due within one year	1
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years	137
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years	24
Available-for-sale, fair value, remaining contractual maturity, due after ten years	$ 0
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]
Available-for-sale, weighted average yield	2.31%
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year	1.51%
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years	2.50%
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years	1.23%
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years	0.00%
Securities of U.S. states and political subdivisions [Member]
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Available-for-sale, at amortized cost, net	$ 11,218	16,618
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year	1,169
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years	2,554
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years	5,064
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years	2,431
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]
Available-for-sale, fair value	10,666	16,917
Available-for-sale, fair value, remaining contractual maturity, due within one year	1,167
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years	2,539
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years	4,708
Available-for-sale, fair value, remaining contractual maturity, due after ten years	$ 2,252
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]
Available-for-sale, weighted average yield	2.74%
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year	3.14%
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years	2.64%
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years	2.59%
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years	2.96%
Federal agency mortgage-backed securities [Member]
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Available-for-sale, at amortized cost, net	$ 56,283	104,661
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year	0
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years	306
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years	898
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years	55,079
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]
Available-for-sale, fair value	50,351	105,886
Available-for-sale, fair value, remaining contractual maturity, due within one year	0
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years	293
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years	831
Available-for-sale, fair value, remaining contractual maturity, due after ten years	$ 49,227
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]
Available-for-sale, weighted average yield	3.25%
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year	0.00%
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years	1.87%
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years	2.45%
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years	3.27%
Non-agency mortgage-backed securities [Member]
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Available-for-sale, at amortized cost, net	$ 3,546	4,515
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year	0
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years	0
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years	72
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years	3,474
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]
Available-for-sale, fair value	3,426	4,532
Available-for-sale, fair value, remaining contractual maturity, due within one year	0
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years	0
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years	68
Available-for-sale, fair value, remaining contractual maturity, due after ten years	$ 3,358
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]
Available-for-sale, weighted average yield	3.65%
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year	0.00%
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years	0.00%
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years	3.43%
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years	3.66%
Collateralized loan obligations [Member]
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Available-for-sale, at amortized cost, net	$ 4,270	5,713
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year	0
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years	2
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years	3,865
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years	403
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]
Available-for-sale, fair value	4,134	5,708
Available-for-sale, fair value, remaining contractual maturity, due within one year	0
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years	2
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years	3,749
Available-for-sale, fair value, remaining contractual maturity, due after ten years	$ 383
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]
Available-for-sale, weighted average yield	4.01%
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year	0.00%
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years	4.44%
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years	4.00%
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years	4.01%
Other debt securities [Member]
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Available-for-sale, at amortized cost, net	$ 2,325	4,217
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year	84
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years	216
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years	829
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years	1,196
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]
Available-for-sale, fair value	2,366	$ 4,469
Available-for-sale, fair value, remaining contractual maturity, due within one year	82
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years	212
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years	827
Available-for-sale, fair value, remaining contractual maturity, due after ten years	$ 1,245
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]
Available-for-sale, weighted average yield	3.68%
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year	3.58%
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years	4.42%
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years	2.94%
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years	4.06%