Loans and Related Allowance for Credit Losses, Commercial Loan Categories by Risk Categories and Vintage (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Financing Receivable and Net Investment in Lease, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total loans	$ 945,906	$ 895,394	$ 862,827
Total Commercial [Member]
Financing Receivable and Net Investment in Lease, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Term loans by origination year, current fiscal year, total	91,627	119,666
Term loans by origination year, fiscal year before current fiscal year, total	80,461	40,707
Term loans by origination year, two years before current fiscal year, total	31,682	51,742
Term loans by origination year, three years before current fiscal year, total	37,538	27,066
Term loans by origination year, four years before current fiscal year, total	18,852	14,179
Term loans by origination year, more than five years before current fiscal year, total	29,463	35,226
Revolving loans, total	259,433	223,833
Revolving loans converted to term loans, total	914	701
Total loans	549,970	513,120
Total Commercial [Member] | Pass [Member]
Financing Receivable and Net Investment in Lease, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total loans	527,100
Total Commercial [Member] | Criticized [Member]
Financing Receivable and Net Investment in Lease, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total loans	22,800
Commercial and industrial loans [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Term loans by origination year, current fiscal year, finance receivable	53,593	67,219
Term loans by origination year, fiscal year before current fiscal year, finance receivable	33,727	16,077
Term loans by origination year, two years before current fiscal year, finance receivable	10,947	21,790
Term loans by origination year, three years before current fiscal year, finance receivable	14,987	8,656
Term loans by origination year, four years before current fiscal year, finance receivable	5,129	4,482
Term loans by origination year, more than five years before current fiscal year, finance receivable	7,578	14,536
Revolving loans, finance receivable	252,842	216,980
Revolving loans converted to term loans, finance receivable	891	696
Loans	379,694	350,436
Commercial and industrial loans [Member] | Pass [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Term loans by origination year, current fiscal year, finance receivable	52,868	65,562
Term loans by origination year, fiscal year before current fiscal year, finance receivable	32,696	15,193
Term loans by origination year, two years before current fiscal year, finance receivable	10,356	20,553
Term loans by origination year, three years before current fiscal year, finance receivable	14,288	7,400
Term loans by origination year, four years before current fiscal year, finance receivable	4,400	3,797
Term loans by origination year, more than five years before current fiscal year, finance receivable	6,921	13,985
Revolving loans, finance receivable	246,965	211,452
Revolving loans converted to term loans, finance receivable	891	679
Loans	369,385	338,621
Commercial and industrial loans [Member] | Criticized [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Term loans by origination year, current fiscal year, finance receivable	725	1,657
Term loans by origination year, fiscal year before current fiscal year, finance receivable	1,031	884
Term loans by origination year, two years before current fiscal year, finance receivable	591	1,237
Term loans by origination year, three years before current fiscal year, finance receivable	699	1,256
Term loans by origination year, four years before current fiscal year, finance receivable	729	685
Term loans by origination year, more than five years before current fiscal year, finance receivable	657	551
Revolving loans, finance receivable	5,877	5,528
Revolving loans converted to term loans, finance receivable	0	17
Loans	10,309	11,815
Real estate mortgage [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Term loans by origination year, current fiscal year, finance receivable	30,261	41,658
Term loans by origination year, fiscal year before current fiscal year, finance receivable	35,647	17,048
Term loans by origination year, two years before current fiscal year, finance receivable	14,531	21,988
Term loans by origination year, three years before current fiscal year, finance receivable	16,970	14,452
Term loans by origination year, four years before current fiscal year, finance receivable	11,741	8,326
Term loans by origination year, more than five years before current fiscal year, finance receivable	19,371	18,447
Revolving loans, finance receivable	5,226	5,811
Revolving loans converted to term loans, finance receivable	23	3
Loans	133,770	127,733
Real estate mortgage [Member] | Pass [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Term loans by origination year, current fiscal year, finance receivable	28,890	38,196
Term loans by origination year, fiscal year before current fiscal year, finance receivable	33,333	15,929
Term loans by origination year, two years before current fiscal year, finance receivable	13,802	19,013
Term loans by origination year, three years before current fiscal year, finance receivable	14,402	12,618
Term loans by origination year, four years before current fiscal year, finance receivable	10,643	7,451
Term loans by origination year, more than five years before current fiscal year, finance receivable	17,535	16,026
Revolving loans, finance receivable	5,055	5,411
Revolving loans converted to term loans, finance receivable	23	3
Loans	123,683	114,647
Real estate mortgage [Member] | Criticized [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Term loans by origination year, current fiscal year, finance receivable	1,371	3,462
Term loans by origination year, fiscal year before current fiscal year, finance receivable	2,314	1,119
Term loans by origination year, two years before current fiscal year, finance receivable	729	2,975
Term loans by origination year, three years before current fiscal year, finance receivable	2,568	1,834
Term loans by origination year, four years before current fiscal year, finance receivable	1,098	875
Term loans by origination year, more than five years before current fiscal year, finance receivable	1,836	2,421
Revolving loans, finance receivable	171	400
Revolving loans converted to term loans, finance receivable	0	0
Loans	10,087	13,086
Real estate construction [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Term loans by origination year, current fiscal year, finance receivable	4,278	6,405
Term loans by origination year, fiscal year before current fiscal year, finance receivable	7,225	4,324
Term loans by origination year, two years before current fiscal year, finance receivable	3,764	5,135
Term loans by origination year, three years before current fiscal year, finance receivable	3,753	2,401
Term loans by origination year, four years before current fiscal year, finance receivable	969	447
Term loans by origination year, more than five years before current fiscal year, finance receivable	535	336
Revolving loans, finance receivable	1,365	1,042
Revolving loans converted to term loans, finance receivable	0	2
Loans	21,889	20,092
Real estate construction [Member] | Pass [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Term loans by origination year, current fiscal year, finance receivable	3,686	5,895
Term loans by origination year, fiscal year before current fiscal year, finance receivable	6,855	4,058
Term loans by origination year, two years before current fiscal year, finance receivable	3,591	4,549
Term loans by origination year, three years before current fiscal year, finance receivable	3,533	2,167
Term loans by origination year, four years before current fiscal year, finance receivable	906	379
Term loans by origination year, more than five years before current fiscal year, finance receivable	533	329
Revolving loans, finance receivable	1,352	1,042
Revolving loans converted to term loans, finance receivable	0	2
Loans	20,456	18,421
Real estate construction [Member] | Criticized [Member]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Term loans by origination year, current fiscal year, finance receivable	592	510
Term loans by origination year, fiscal year before current fiscal year, finance receivable	370	266
Term loans by origination year, two years before current fiscal year, finance receivable	173	586
Term loans by origination year, three years before current fiscal year, finance receivable	220	234
Term loans by origination year, four years before current fiscal year, finance receivable	63	68
Term loans by origination year, more than five years before current fiscal year, finance receivable	2	7
Revolving loans, finance receivable	13	0
Revolving loans converted to term loans, finance receivable	0	0
Loans	1,433	1,671
Lease financing [Member]
Net Investment in Lease, before Allowance for Credit Loss [Abstract]
Term loans by origination year, current fiscal year, net investment in lease	3,495	4,384
Term loans by origination year, fiscal year before current fiscal year, net investment in lease	3,862	3,258
Term loans by origination year, two years before current fiscal year, net investment in lease	2,440	2,829
Term loans by origination year, three years before current fiscal year, net investment in lease	1,828	1,557
Term loans by origination year, four years before current fiscal year, net investment in lease	1,013	924
Term loans by origination year, more than five years before current fiscal year, net investment in lease	1,979	1,907
Revolving loans, net investment in lease	0	0
Revolving loans converted to term loans, net investment in lease	0	0
Lease financing	14,617	14,859
Lease financing [Member] | Pass [Member]
Net Investment in Lease, before Allowance for Credit Loss [Abstract]
Term loans by origination year, current fiscal year, net investment in lease	3,274	4,100
Term loans by origination year, fiscal year before current fiscal year, net investment in lease	3,591	3,012
Term loans by origination year, two years before current fiscal year, net investment in lease	2,267	2,547
Term loans by origination year, three years before current fiscal year, net investment in lease	1,651	1,373
Term loans by origination year, four years before current fiscal year, net investment in lease	905	838
Term loans by origination year, more than five years before current fiscal year, net investment in lease	1,930	1,805
Revolving loans, net investment in lease	0	0
Revolving loans converted to term loans, net investment in lease	0	0
Lease financing	13,618	13,675
Lease financing [Member] | Criticized [Member]
Net Investment in Lease, before Allowance for Credit Loss [Abstract]
Term loans by origination year, current fiscal year, net investment in lease	221	284
Term loans by origination year, fiscal year before current fiscal year, net investment in lease	271	246
Term loans by origination year, two years before current fiscal year, net investment in lease	173	282
Term loans by origination year, three years before current fiscal year, net investment in lease	177	184
Term loans by origination year, four years before current fiscal year, net investment in lease	108	86
Term loans by origination year, more than five years before current fiscal year, net investment in lease	49	102
Revolving loans, net investment in lease	0	0
Revolving loans converted to term loans, net investment in lease	0	0
Lease financing	$ 999	$ 1,184