Fair Value of Assets and Liabilities - Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	$ 1,421	$ 1,601
Loans held-for-sale	89	258
Securities available for sale at fair value	8,718	8,707
Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	89	258
Securities available for sale at fair value	8,718	8,707
Total other assets	446	474
Total assets	10,674	11,040
Total other liabilities	1,049	128
Total liabilities	1,432	554
Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	0	0
Securities available for sale at fair value	0	0
Total other assets	177	162
Total assets	177	162
Total other liabilities	39	11
Total liabilities	39	11
Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	69	230
Securities available for sale at fair value	8,718	8,707
Total other assets	269	312
Total assets	10,454	10,812
Total other liabilities	990	94
Total liabilities	1,373	520
Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	20	28
Securities available for sale at fair value	0	0
Total other assets	0	0
Total assets	43	66
Total other liabilities	20	23
Total liabilities	20	23
Deferred compensation mutual funds | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	106	125
Deferred compensation mutual funds | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	106	125
Deferred compensation mutual funds | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0	0
Deferred compensation mutual funds | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0	0
Equity, mutual funds, and other | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	22	25
Equity, mutual funds, and other | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	22	25
Equity, mutual funds, and other | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0	0
Equity, mutual funds, and other | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0	0
Derivatives, forwards and futures | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	49	12
Total other liabilities	39	11
Derivatives, forwards and futures | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	49	12
Total other liabilities	39	11
Derivatives, forwards and futures | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0	0
Total other liabilities	0	0
Derivatives, forwards and futures | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0	0
Total other liabilities	0	0
Derivatives, interest rate contracts | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	267	311
Total other liabilities	988	93
Derivatives, interest rate contracts | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0	0
Total other liabilities	0	0
Derivatives, interest rate contracts | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	267	311
Total other liabilities	988	93
Derivatives, interest rate contracts | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0	0
Total other liabilities	0	0
Derivatives, other | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	2	1
Total other liabilities	22	24
Derivatives, other | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0	0
Total other liabilities	0	0
Derivatives, other | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	2	1
Total other liabilities	2	1
Derivatives, other | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0	0
Total other liabilities	20	23
Government agency issued MBS | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	4,690	5,055
Government agency issued MBS | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	0	0
Government agency issued MBS | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	4,690	5,055
Government agency issued MBS | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	0	0
Government agency issued CMO | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	2,415	2,257
Government agency issued CMO | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	0	0
Government agency issued CMO | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	2,415	2,257
Government agency issued CMO | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	0	0
Other U.S. government agencies | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	1,056	850
Other U.S. government agencies | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	0	0
Other U.S. government agencies | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	1,056	850
Other U.S. government agencies | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	0	0
States and municipalities | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	557	545
States and municipalities | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	0	0
States and municipalities | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	557	545
States and municipalities | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale at fair value	0	0
Specialty Banking | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,421	1,601
Total trading liabilities	383	426
Specialty Banking | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Total trading liabilities	0	0
Specialty Banking | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,398	1,563
Total trading liabilities	383	426
Specialty Banking | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	23	38
Total trading liabilities	0	0
Specialty Banking | U.S. treasuries | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	53	85
Total trading liabilities	326	334
Specialty Banking | U.S. treasuries | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Total trading liabilities	0	0
Specialty Banking | U.S. treasuries | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	53	85
Total trading liabilities	326	334
Specialty Banking | U.S. treasuries | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Total trading liabilities	0	0
Specialty Banking | Government agency issued MBS | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	60	464
Total trading liabilities		1
Specialty Banking | Government agency issued MBS | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Total trading liabilities		0
Specialty Banking | Government agency issued MBS | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	60	464
Total trading liabilities		1
Specialty Banking | Government agency issued MBS | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Total trading liabilities		0
Specialty Banking | Government agency issued CMO | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	236	62
Specialty Banking | Government agency issued CMO | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Specialty Banking | Government agency issued CMO | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	236	62
Specialty Banking | Government agency issued CMO | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Specialty Banking | Other U.S. government agencies | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	147	276
Specialty Banking | Other U.S. government agencies | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Specialty Banking | Other U.S. government agencies | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	147	276
Specialty Banking | Other U.S. government agencies | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Specialty Banking | States and municipalities | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	31	34
Specialty Banking | States and municipalities | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Specialty Banking | States and municipalities | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	31	34
Specialty Banking | States and municipalities | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Specialty Banking | Corporate and other debt | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	871	642
Total trading liabilities	57	91
Specialty Banking | Corporate and other debt | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Total trading liabilities	0	0
Specialty Banking | Corporate and other debt | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	871	642
Total trading liabilities	57	91
Specialty Banking | Corporate and other debt | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Total trading liabilities	0	0
Specialty Banking | Interest-only strips | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	23	38
Specialty Banking | Interest-only strips | Level 1 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Specialty Banking | Interest-only strips | Level 2 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0	0
Specialty Banking | Interest-only strips | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	$ 23	$ 38