Loans and Leases - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable
Unearned income	$ 398	$ 384
Accrued interest receivable	775	534
Net discount	355	216
Solar energy installation loans
Accounts, Notes, Loans and Financing Receivable
Net discount	838	872
Federal Home Loan Bank Advances
Accounts, Notes, Loans and Financing Receivable
Loans pledged	16,100	14,900
FRB Loan
Accounts, Notes, Loans and Financing Receivable
Loans pledged	$ 80,200	$ 60,100

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
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Amount of unamortized loan commitment, origination, and other costs (fees) and purchase premium (discount) on financing receivable recognized as adjustment to yield. Excludes financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481598/310-20-45-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
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Reference 3: http://www.xbrl.org/2003/role/recommendedDisclosureRef
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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 1
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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