Credit Quality and the Allowance for Loan and Lease Losses - Summary of the ALLL and Related Loans and Leases Classified by Portfolio Segment (Details) - USD ($) $ in Millions	Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated	$ 122		$ 164
Collectively evaluated	2,072		1,728
Total ALLL	2,194	[1]	1,892	[1]	$ 2,453	$ 1,202
Individually evaluated	1,388		1,352
Collectively evaluated	119,969		110,544
Total portfolio loans and leases	121,357		111,896
Leveraged leases	247		285
Commercial Leveraged Leases
Financing Receivable, Allowance for Credit Loss [Line Items]
Total ALLL	2		2
Leveraged leases	247		285
Commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated	30		77
Collectively evaluated	1,097		1,025
Total ALLL	1,127		1,102		1,456	710
Individually evaluated	531		579
Collectively evaluated	75,858		69,689
Total portfolio loans and leases	76,389		70,268
Residential Mortgage
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated	47		46
Collectively evaluated	198		189
Total ALLL	245		235		294	73
Individually evaluated	560		460
Collectively evaluated	16,945		15,783
Total portfolio loans and leases	17,505		16,243
Loans	123		154
Consumer
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated	45		41
Collectively evaluated	777		514
Total ALLL	822		555		$ 703	$ 298
Individually evaluated	297		313
Collectively evaluated	27,166		25,072
Total portfolio loans and leases	$ 27,463		$ 25,385

[1] Includes $17 and $24 of other short-term investments, $185 and $322 of portfolio loans and leases, $(2) and $(2) of ALLL, $2 and $2 of other assets, $9 and $1 of other liabilities and $118 and $263 of long-term debt from consolidated VIEs that are included in their respective captions above at December 31, 2022 and 2021, respectively. For further information, refer to Note 12.