Derivative Financial Instruments - Classifications and Hedging Relationships (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	$ 333,012	$ 300,572
Derivative Asset, Fair Value, Gross	2,453	4,027
Derivative Liability, Fair Value, Gross	(4,749)	(3,536)
Derivative Asset [Abstract]
Amounts subject to master netting arrangements	(1,223)	(1,312)
Cash collateral (received) posted for amounts subject to master netting arrangements	(546)	(345)
Net Amount in Consolidated Balance Sheets	684	2,370
Derivative Liability [Abstract]
Amounts subject to master netting arrangements	1,223	1,312
Cash collateral (received) posted for amounts subject to master netting arrangements	$ 555	$ 1,638
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other Liabilities	Other Liabilities
Net amount	Other assets (including $1,582 and $3,436 at fair value, respectively)	Other assets (including $1,582 and $3,436 at fair value, respectively)
Net amount	$ (2,971)	$ (586)
Cash flow hedges | Interest rate contracts | Swap | Commercial loans
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	16,650	0
Derivative Asset, Fair Value, Gross	0	0
Derivative Liability, Fair Value, Gross	0	0
Fair value hedges | Interest rate contracts
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	23,490	25,401
Derivative Asset, Fair Value, Gross	0	0
Derivative Liability, Fair Value, Gross	(68)	(8)
Fair value hedges | Interest rate contracts | Swap | Long-term debt
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	16,393	12,690
Derivative Asset, Fair Value, Gross	0	0
Derivative Liability, Fair Value, Gross	(68)	(6)
Fair value hedges | Interest rate contracts | Swap | AFS securities
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	7,097	12,711
Derivative Asset, Fair Value, Gross	0	0
Derivative Liability, Fair Value, Gross	0	(2)
Not designated as hedges
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	292,872	275,171
Derivative Asset, Fair Value, Gross	2,453	4,027
Derivative Liability, Fair Value, Gross	(4,681)	(3,528)
Not designated as hedges | Client-related and other risk management
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	257,003	244,348
Derivative Asset, Fair Value, Gross	2,293	3,981
Derivative Liability, Fair Value, Gross	(4,592)	(3,506)
Not designated as hedges | Client-related and other risk management | Interest rate contracts | Swap
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	155,670	150,223
Derivative Asset, Fair Value, Gross	579	1,716
Derivative Liability, Fair Value, Gross	(2,665)	(733)
Not designated as hedges | Client-related and other risk management | Interest rate contracts | Options
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	29,840	23,659
Derivative Asset, Fair Value, Gross	172	43
Derivative Liability, Fair Value, Gross	(192)	(30)
Not designated as hedges | Client-related and other risk management | Interest rate contracts | Forward commitments
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	1,495	2,404
Derivative Asset, Fair Value, Gross	8	2
Derivative Liability, Fair Value, Gross	(2)	(5)
Not designated as hedges | Client-related and other risk management | Interest rate contracts | Other
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	3,823	2,927
Derivative Asset, Fair Value, Gross	1	0
Derivative Liability, Fair Value, Gross	0	0
Not designated as hedges | Client-related and other risk management | Equity contracts
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	33,185	34,232
Derivative Asset, Fair Value, Gross	644	1,582
Derivative Liability, Fair Value, Gross	(901)	(2,089)
Not designated as hedges | Client-related and other risk management | Credit Contract | Trading assets
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	140	0
Derivative Asset, Fair Value, Gross	0	0
Derivative Liability, Fair Value, Gross	0	0
Not designated as hedges | Client-related and other risk management | Credit Contract | Loans and leases
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	394	570
Derivative Asset, Fair Value, Gross	0	0
Derivative Liability, Fair Value, Gross	0	(2)
Not designated as hedges | Client-related and other risk management | Credit Contract | Risk participation agreements
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	6,824	8,145
Derivative Asset, Fair Value, Gross	0	0
Derivative Liability, Fair Value, Gross	(3)	(4)
Not designated as hedges | Client-related and other risk management | Credit Contract | Total Return Swap
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	1,729	1,445
Derivative Asset, Fair Value, Gross	81	3
Derivative Liability, Fair Value, Gross	(2)	(19)
Not designated as hedges | Client-related and other risk management | Foreign exchange contracts
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	19,022	16,102
Derivative Asset, Fair Value, Gross	364	160
Derivative Liability, Fair Value, Gross	(380)	(156)
Not designated as hedges | Client-related and other risk management | Commodity Contract
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	4,881	4,641
Derivative Asset, Fair Value, Gross	444	475
Derivative Liability, Fair Value, Gross	(447)	(468)
Not designated as hedges | Mortgage banking | Interest rate contracts
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	3,382	11,941
Derivative Asset, Fair Value, Gross	27	38
Derivative Liability, Fair Value, Gross	(23)	(22)
Not designated as hedges | Mortgage banking | Interest rate contracts | Swap
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	115	441
Derivative Asset, Fair Value, Gross	0	0
Derivative Liability, Fair Value, Gross	0	0
Not designated as hedges | Mortgage banking | Interest rate contracts | Other
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	140	424
Derivative Asset, Fair Value, Gross	1	1
Derivative Liability, Fair Value, Gross	0	0
Not designated as hedges | Mortgage banking | Interest rate contracts | Interest rate lock commitments
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	999	4,163
Derivative Asset, Fair Value, Gross	1	30
Derivative Liability, Fair Value, Gross	(17)	(7)
Not designated as hedges | Mortgage banking | Interest rate contracts | When issued securities, forward rate agreements and forward commitments
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	2,128	6,913
Derivative Asset, Fair Value, Gross	25	7
Derivative Liability, Fair Value, Gross	(6)	(15)
Not designated as hedges | Loan Servicing Rights | Interest rate contracts
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	32,487	18,882
Derivative Asset, Fair Value, Gross	133	8
Derivative Liability, Fair Value, Gross	(66)	0
Not designated as hedges | Loan Servicing Rights | Interest rate contracts | Swap
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	14,566	12,837
Derivative Asset, Fair Value, Gross	0	0
Derivative Liability, Fair Value, Gross	0	0
Not designated as hedges | Loan Servicing Rights | Interest rate contracts | Options
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	13,930	101
Derivative Asset, Fair Value, Gross	122	1
Derivative Liability, Fair Value, Gross	(48)	0
Not designated as hedges | Loan Servicing Rights | Interest rate contracts | Other
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	1,532	2,017
Derivative Asset, Fair Value, Gross	0	0
Derivative Liability, Fair Value, Gross	(3)	0
Not designated as hedges | Loan Servicing Rights | Interest rate contracts | When issued securities, forward rate agreements and forward commitments
Derivative Instruments, Notional, Fair Value Assets and Liabilities[Line Items]
Notional Amount	2,459	3,927
Derivative Asset, Fair Value, Gross	11	7
Derivative Liability, Fair Value, Gross	$ (15)	$ 0