Loans and Leases - Additional Information (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable
Unearned income	$ 383	$ 380
Accrued interest receivable	571	566
Net discount	234	324
Solar energy installation loans
Accounts, Notes, Loans and Financing Receivable
Net discount	893	901
Federal Home Loan Bank Advances
Accounts, Notes, Loans and Financing Receivable
Loans pledged	15,000	15,100
FRB Loan
Accounts, Notes, Loans and Financing Receivable
Loans pledged	$ 59,600	$ 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
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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
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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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