Loans and Related Allowance for Credit Losses (Rollforward of Allowance for Credit Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 5,361		$ 2,742		$ 2,629
Acquisition PCD reserves	1,056
Charge-offs	(1,101)		(1,192)		(974)
Recoveries	444		360		332
Net (charge-offs)	(657)		(832)		(642)
Provision for (recapture of) credit losses	(887)		2,985		773
Net (increase) / decrease in allowance for unfunded loan commitments and letters of credit					(33)
Other	(5)		3		15
Ending balance	4,868		5,361		2,742
Loans collectively evaluated for impairment - associated allowance					2,277
Loans collectively evaluated for impairment					235,498
Fair value option loans					742
Purchased impaired loans					1,719
Total loans, net	288,372	[1]	241,928	[1]	239,843
Allowance For Unfunded Lending Related Commitments [Roll Forward]
Beginning balance	584		318
Acquisition PCD reserves	46
Provision for (recapture of) credit losses	32		87
Ending balance	662		584		318
Allowance for credit loss and off-balance sheet liability	5,530		5,945
Allowances for investment securities and other financial assets	171		109
TDRs
Allowance for Loan and Lease Losses [Roll Forward]
Loans individually evaluated for impairment - associated allowance					133
Loans individually evaluated for impairment					1,664
Other Loans
Allowance for Loan and Lease Losses [Roll Forward]
Loans individually evaluated for impairment - associated allowance					58
Loans individually evaluated for impairment					220
Purchased impaired loans
Allowance for Loan and Lease Losses [Roll Forward]
Impaired loans - associated allowance					274
Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance			463
Ending balance					463
Allowance For Unfunded Lending Related Commitments [Roll Forward]
Beginning balance			179
Ending balance					179
Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	5,361		3,205
Ending balance			5,361		3,205
Allowance For Unfunded Lending Related Commitments [Roll Forward]
Beginning balance	584		497
Ending balance			584		497
Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,337		1,812		1,663
Acquisition PCD reserves	774
Charge-offs	(434)		(407)		(216)
Recoveries	106		94		78
Net (charge-offs)	(328)		(313)		(138)
Provision for (recapture of) credit losses	(594)		2,139		320
Net (increase) / decrease in allowance for unfunded loan commitments and letters of credit					(34)
Other	(4)		3		1
Ending balance	3,185		3,337		1,812
Loans collectively evaluated for impairment - associated allowance					1,714
Loans collectively evaluated for impairment					160,021
Total loans, net	193,078		167,203		160,602
Allowance For Unfunded Lending Related Commitments [Roll Forward]
Beginning balance	485		316
Acquisition PCD reserves	43
Provision for (recapture of) credit losses	36		116
Ending balance	564		485		316
Allowance for credit loss and off-balance sheet liability	3,749		3,822
Commercial | TDRs
Allowance for Loan and Lease Losses [Roll Forward]
Loans individually evaluated for impairment - associated allowance					40
Loans individually evaluated for impairment					361
Commercial | Other Loans
Allowance for Loan and Lease Losses [Roll Forward]
Loans individually evaluated for impairment - associated allowance					58
Loans individually evaluated for impairment					220
Commercial | Purchased impaired loans
Allowance for Loan and Lease Losses [Roll Forward]
Impaired loans - associated allowance
Commercial | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance			(304)
Ending balance					(304)
Allowance For Unfunded Lending Related Commitments [Roll Forward]
Beginning balance			53
Ending balance					53
Commercial | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,337		1,508
Ending balance			3,337		1,508
Allowance For Unfunded Lending Related Commitments [Roll Forward]
Beginning balance	485		369
Ending balance			485		369
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	2,024		930		966
Acquisition PCD reserves	282
Charge-offs	(667)		(785)		(758)
Recoveries	338		266		254
Net (charge-offs)	(329)		(519)		(504)
Provision for (recapture of) credit losses	(293)		846		453
Net (increase) / decrease in allowance for unfunded loan commitments and letters of credit					1
Other	(1)				14
Ending balance	1,683		2,024		930
Loans collectively evaluated for impairment - associated allowance					563
Loans collectively evaluated for impairment					75,477
Fair value option loans					742
Purchased impaired loans					1,719
Total loans, net	95,294		74,725		79,241
Allowance For Unfunded Lending Related Commitments [Roll Forward]
Beginning balance	99		2
Acquisition PCD reserves	3
Provision for (recapture of) credit losses	(4)		(29)
Ending balance	98		99		2
Allowance for credit loss and off-balance sheet liability	1,781		2,123
Consumer | TDRs
Allowance for Loan and Lease Losses [Roll Forward]
Loans individually evaluated for impairment - associated allowance					93
Loans individually evaluated for impairment					1,303
Consumer | Purchased impaired loans
Allowance for Loan and Lease Losses [Roll Forward]
Impaired loans - associated allowance					274
Consumer | Cumulative Effect, Period of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance			767
Ending balance					767
Allowance For Unfunded Lending Related Commitments [Roll Forward]
Beginning balance			126
Ending balance					126
Consumer | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	2,024		1,697
Ending balance			2,024		1,697
Allowance For Unfunded Lending Related Commitments [Roll Forward]
Beginning balance	$ 99		128
Ending balance			$ 99		$ 128

[1] Our consolidated assets included the following for which we have elected the fair value option: Loans held for sale of $1.9 billion, Loans of $1.5 billion and Other assets of $0.1 billion at December 31, 2021 and Loans held for sale of $1.2 billion, Loans of $1.4 billion and Other assets of $0.1 billion at December 31, 2020.