Loans and Related Allowance for Credit Losses, Loans by Credit Quality Indicator, Commercial (Details) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Abstract]
Total	[1]	$ 1,009,843	$ 962,265
Total Commercial [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		43,629
Term loans by origination year, 2019		100,041
Term loans by origination year, 2018		58,274
Term loans by origination year, 2017		33,315
Term loans by origination year, 2016		27,451
Term loans by origination year, Prior		31,483
Revolving loans		273,198
Revolving loans converted to term loans		344
Total		567,735	515,719
Total Commercial [Member] | Pass [Member]
Loans and Leases Receivable Disclosure [Abstract]
Total			495,201
Total Commercial [Member] | Criticized [Member]
Loans and Leases Receivable Disclosure [Abstract]
Total			20,518
Commercial and industrial loans [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		33,416
Term loans by origination year, 2019		54,957
Term loans by origination year, 2018		24,736
Term loans by origination year, 2017		12,324
Term loans by origination year, 2016		8,248
Term loans by origination year, Prior		5,519
Revolving loans		265,611
Revolving loans converted to term loans		209
Total		405,020	354,125
Commercial and industrial loans [Member] | Pass [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		32,531
Term loans by origination year, 2019		53,904
Term loans by origination year, 2018		23,788
Term loans by origination year, 2017		11,603
Term loans by origination year, 2016		7,815
Term loans by origination year, Prior		5,061
Revolving loans		250,893
Revolving loans converted to term loans		209
Total		385,804	338,740
Commercial and industrial loans [Member] | Criticized [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		885
Term loans by origination year, 2019		1,053
Term loans by origination year, 2018		948
Term loans by origination year, 2017		721
Term loans by origination year, 2016		433
Term loans by origination year, Prior		458
Revolving loans		14,718
Revolving loans converted to term loans		0
Total		19,216	15,385
Commercial real estate mortgage [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		7,396
Term loans by origination year, 2019		31,772
Term loans by origination year, 2018		23,783
Term loans by origination year, 2017		15,318
Term loans by origination year, 2016		15,922
Term loans by origination year, Prior		22,612
Revolving loans		5,836
Revolving loans converted to term loans		128
Total		122,767	121,824
Commercial real estate mortgage [Member] | Pass [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		7,336
Term loans by origination year, 2019		31,320
Term loans by origination year, 2018		23,268
Term loans by origination year, 2017		14,577
Term loans by origination year, 2016		15,376
Term loans by origination year, Prior		21,087
Revolving loans		5,563
Revolving loans converted to term loans		128
Total		118,655	118,054
Commercial real estate mortgage [Member] | Criticized [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		60
Term loans by origination year, 2019		452
Term loans by origination year, 2018		515
Term loans by origination year, 2017		741
Term loans by origination year, 2016		546
Term loans by origination year, Prior		1,525
Revolving loans		273
Revolving loans converted to term loans		0
Total		4,112	3,770
Commercial real estate construction [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		1,295
Term loans by origination year, 2019		7,324
Term loans by origination year, 2018		5,621
Term loans by origination year, 2017		3,030
Term loans by origination year, 2016		1,298
Term loans by origination year, Prior		486
Revolving loans		1,751
Revolving loans converted to term loans		7
Total		20,812	19,939
Commercial real estate construction [Member] | Pass [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		1,293
Term loans by origination year, 2019		7,226
Term loans by origination year, 2018		5,528
Term loans by origination year, 2017		3,024
Term loans by origination year, 2016		1,290
Term loans by origination year, Prior		472
Revolving loans		1,750
Revolving loans converted to term loans		7
Total		20,590	19,752
Commercial real estate construction [Member] | Criticized [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		2
Term loans by origination year, 2019		98
Term loans by origination year, 2018		93
Term loans by origination year, 2017		6
Term loans by origination year, 2016		8
Term loans by origination year, Prior		14
Revolving loans		1
Revolving loans converted to term loans		0
Total		222	187
Commercial lease financing receivable [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		1,522
Term loans by origination year, 2019		5,988
Term loans by origination year, 2018		4,134
Term loans by origination year, 2017		2,643
Term loans by origination year, 2016		1,983
Term loans by origination year, Prior		2,866
Revolving loans		0
Revolving loans converted to term loans		0
Total		19,136	19,831
Commercial lease financing receivable [Member] | Pass [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		1,439
Term loans by origination year, 2019		5,566
Term loans by origination year, 2018		3,769
Term loans by origination year, 2017		2,447
Term loans by origination year, 2016		1,844
Term loans by origination year, Prior		2,739
Revolving loans		0
Revolving loans converted to term loans		0
Total		17,804	18,655
Commercial lease financing receivable [Member] | Criticized [Member]
Loans and Leases Receivable Disclosure [Abstract]
Term loans by origination year, 2020		83
Term loans by origination year, 2019		422
Term loans by origination year, 2018		365
Term loans by origination year, 2017		196
Term loans by origination year, 2016		139
Term loans by origination year, Prior		127
Revolving loans		0
Revolving loans converted to term loans		0
Total		$ 1,332	$ 1,176

[1] (2) Parenthetical amounts represent assets and liabilities that we are required to carry at fair value or have elected the fair value option.