Loans and Leases - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable
Unearned income	$ 383	$ 380
Accrued interest receivable	568	566
Net discount	279	324
Solar energy installation loans
Accounts, Notes, Loans and Financing Receivable
Net discount	898	901
Federal Home Loan Bank Advances
Accounts, Notes, Loans and Financing Receivable
Loans pledged	14,800	15,100
FRB Loan
Accounts, Notes, Loans and Financing Receivable
Loans pledged	$ 58,300	$ 55,300

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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+ 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
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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.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
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