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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 360
-SubTopic 10
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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Loans and Leases - Schedule of Loans by Portfolio Segment (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 64,156	$ 62,565
Allowance for loan and lease losses	(738)	(815)	$ (773)	$ (685)
Net loans and leases	63,418	61,750
Commercial \| Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	31,202	29,957
Commercial \| Commercial and industrial \| Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Property, plant, and equipment and finance lease right-of-use asset	1,500	1,400
Commercial \| Loans to mortgage companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	4,703	3,471
Commercial \| Commercial, financial, and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	35,905	33,428
Allowance for loan and lease losses	(335)	(345)	(339)	(308)
Commercial \| Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	13,563	14,421
Allowance for loan and lease losses	(177)	(227)	(172)	(146)
Commercial \| Credit card and other:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	143	174
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	14,108	14,047
Consumer \| HELOC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	2,164	2,092
Consumer \| Real estate installment loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	11,944	11,955
Consumer \| Credit card and other:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	580	669
Allowance for loan and lease losses	$ (20)	$ (22)	$ (29)	$ (31)