Loans - Commercial Banking: Risk Profile by Internal Risk Rating (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	$ 314,780	$ 312,331
Commercial Portfolio
Financing Receivable, Allowance for Credit Loss [Line Items]
2023	8,095	20,217
2022	19,101	14,024
2021	11,624	6,570
2020	5,596	7,420
2019	6,060	4,431
Prior	10,840	10,374
Total Term Loans	61,316	63,036
Revolving Loans	29,698	31,594
Revolving Loans Converted to Term	139	46
Total	91,153	94,676
Commercial Portfolio | Commercial and multifamily real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
2023	3,149	6,220
2022	6,065	5,316
2021	3,698	1,888
2020	1,505	3,508
2019	2,967	2,324
Prior	4,983	4,805
Total Term Loans	22,367	24,061
Revolving Loans	13,230	13,367
Revolving Loans Converted to Term	25	25
Total	35,622	37,453
Commercial Portfolio | Commercial and multifamily real estate | Noncriticized
Financing Receivable, Allowance for Credit Loss [Line Items]
2023	2,919	5,860
2022	4,848	4,807
2021	3,092	1,676
2020	1,247	2,879
2019	2,421	1,927
Prior	3,796	3,474
Total Term Loans	18,323	20,623
Revolving Loans	13,215	13,254
Revolving Loans Converted to Term	25	25
Total	31,563	33,902
Commercial Portfolio | Commercial and multifamily real estate | Criticized | Criticized performing
Financing Receivable, Allowance for Credit Loss [Line Items]
2023	230	359
2022	1,217	487
2021	560	212
2020	258	535
2019	419	378
Prior	901	1,196
Total Term Loans	3,585	3,167
Revolving Loans	15	113
Revolving Loans Converted to Term	0	0
Total	3,600	3,280
Commercial Portfolio | Commercial and multifamily real estate | Criticized | Criticized nonperforming
Financing Receivable, Allowance for Credit Loss [Line Items]
2023	0	1
2022	0	22
2021	46	0
2020	0	94
2019	127	19
Prior	286	135
Total Term Loans	459	271
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total	459	271
Commercial Portfolio | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Line Items]
2023	4,946	13,997
2022	13,036	8,708
2021	7,926	4,682
2020	4,091	3,912
2019	3,093	2,107
Prior	5,857	5,569
Total Term Loans	38,949	38,975
Revolving Loans	16,468	18,227
Revolving Loans Converted to Term	114	21
Total	55,531	57,223
Commercial Portfolio | Commercial and industrial | Noncriticized
Financing Receivable, Allowance for Credit Loss [Line Items]
2023	4,704	13,485
2022	12,196	7,993
2021	7,329	4,466
2020	3,796	3,420
2019	2,595	1,797
Prior	5,319	5,349
Total Term Loans	35,939	36,510
Revolving Loans	15,352	17,187
Revolving Loans Converted to Term	114	21
Total	51,405	53,718
Commercial Portfolio | Commercial and industrial | Criticized | Criticized performing
Financing Receivable, Allowance for Credit Loss [Line Items]
2023	242	482
2022	815	686
2021	575	216
2020	270	336
2019	344	228
Prior	457	163
Total Term Loans	2,703	2,111
Revolving Loans	1,060	964
Revolving Loans Converted to Term	0	0
Total	3,763	3,075
Commercial Portfolio | Commercial and industrial | Criticized | Criticized nonperforming
Financing Receivable, Allowance for Credit Loss [Line Items]
2023	0	30
2022	25	29
2021	22	0
2020	25	156
2019	154	82
Prior	81	57
Total Term Loans	307	354
Revolving Loans	56	76
Revolving Loans Converted to Term	0	0
Total	$ 363	$ 430