Commitments and Contingencies - Pledged Assets (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total loans and leases	$ 322,092	$ 325,991
Asset Pledged as Collateral
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Securities, fair value	40,590	38,012
Federal Reserve Bank Advances [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	52,737	49,250
Federal Reserve Bank Advances [Member] \| Asset Pledged as Collateral
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total loans and leases	72,823	71,234
FHLB Advances
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	23,219	20,770
FHLB Advances \| Asset Pledged as Collateral
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total loans and leases	$ 68,987	$ 68,988

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 310
-SubTopic 10
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-Section 45
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Amount of investment in marketable security.

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