Credit Quality and the Allowance for Loan and Lease Losses - Summary of Transactions in the ALLL by Portfolio Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 1,892	[1]	$ 2,453		$ 1,202
Losses charged-off	(362)		(344)		(611)
Recoveries of losses previously charged-off	135		170		140
Provision for (benefit from) loan and lease losses	529		(387)		1,079
Balance, end of period	2,194	[1]	1,892	[1]	2,453
Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period					643
Other Consumer Loans, Point of Sale
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Losses charged-off	(32)		(33)		(42)
Recoveries of losses previously charged-off	32		33		42
Commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	1,102		1,456		710
Losses charged-off	(131)		(119)		(282)
Recoveries of losses previously charged-off	30		52		16
Provision for (benefit from) loan and lease losses	126		(287)		852
Balance, end of period	1,127		1,102		1,456
Initial recognition of ALLL on PCD loans					31
Commercial | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period					160
Residential Mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	235		294		73
Losses charged-off	(3)		(3)		(9)
Recoveries of losses previously charged-off	5		7		7
Provision for (benefit from) loan and lease losses	8		(63)		27
Balance, end of period	245		235		294
Initial recognition of ALLL on PCD loans					2
Residential Mortgage | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period					196
Consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	555		703		298
Losses charged-off	(228)		(222)		(320)
Recoveries of losses previously charged-off	100		111		117
Provision for (benefit from) loan and lease losses	395		(37)		200
Balance, end of period	$ 822		555		703
Initial recognition of ALLL on PCD loans					1
Consumer | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period					408
Unallocated
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period			$ 0		121
Losses charged-off					0
Recoveries of losses previously charged-off					0
Provision for (benefit from) loan and lease losses					0
Balance, end of period					0
Unallocated | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period					$ (121)

[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.