Loans, Leases and Allowance for Credit Losses - Gross Charge-Offs By Origination Year (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	$ 0.0	$ 0.0
Year before current fiscal year, writeoff	1.0	6.5
Two years before current fiscal year, writeoff	30.2	11.4
Three years before current fiscal year, writeoff	15.0	9.1
Four years before current fiscal year, writeoff	12.6	0.1
Five years before current fiscal year, writeoff	6.2	0.3
Revolving Loans Amortized Cost Basis, Writeoff	144.1	0.1
Charge-offs	209.1	27.5
Mortgage finance
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	0.0	0.0
Year before current fiscal year, writeoff	0.0	0.0
Two years before current fiscal year, writeoff	0.0	0.0
Three years before current fiscal year, writeoff	0.0	0.0
Four years before current fiscal year, writeoff	0.0	0.0
Five years before current fiscal year, writeoff	0.0	0.0
Revolving Loans Amortized Cost Basis, Writeoff	0.0	0.0
Charge-offs	0.0	0.0
Municipal & nonprofit
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	0.0	0.0
Year before current fiscal year, writeoff	0.0	0.0
Two years before current fiscal year, writeoff	0.0	0.0
Three years before current fiscal year, writeoff	0.0	0.0
Four years before current fiscal year, writeoff	0.0	0.0
Five years before current fiscal year, writeoff	0.0	0.0
Revolving Loans Amortized Cost Basis, Writeoff	0.0	0.0
Charge-offs	0.0	0.0
Tech & innovation
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	0.0	0.0
Year before current fiscal year, writeoff	1.0	6.5
Two years before current fiscal year, writeoff	3.5	0.0
Three years before current fiscal year, writeoff	0.0	5.5
Four years before current fiscal year, writeoff	0.0	0.1
Five years before current fiscal year, writeoff	0.0	0.0
Revolving Loans Amortized Cost Basis, Writeoff	16.3	0.0
Charge-offs	20.8	12.1
Equity fund resources
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	0.0	0.0
Year before current fiscal year, writeoff	0.0	0.0
Two years before current fiscal year, writeoff	0.0	0.0
Three years before current fiscal year, writeoff	0.0	0.0
Four years before current fiscal year, writeoff	0.0	0.0
Five years before current fiscal year, writeoff	0.0	0.0
Revolving Loans Amortized Cost Basis, Writeoff	0.0	0.0
Charge-offs	0.0	0.0
Other commercial and industrial
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	0.0	0.0
Year before current fiscal year, writeoff	0.0	0.0
Two years before current fiscal year, writeoff	26.7	0.5
Three years before current fiscal year, writeoff	0.0	0.0
Four years before current fiscal year, writeoff	0.0	0.0
Five years before current fiscal year, writeoff	5.6	0.3
Revolving Loans Amortized Cost Basis, Writeoff	127.7	0.1
Charge-offs	160.0	0.9
CRE - owner occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	0.0	0.0
Year before current fiscal year, writeoff	0.0	0.0
Two years before current fiscal year, writeoff	0.0	0.0
Three years before current fiscal year, writeoff	0.0	0.0
Four years before current fiscal year, writeoff	0.0	0.0
Five years before current fiscal year, writeoff	0.0	0.0
Revolving Loans Amortized Cost Basis, Writeoff	0.0	0.0
Charge-offs	0.0	0.0
Hotel franchise finance
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	0.0	0.0
Year before current fiscal year, writeoff	0.0	0.0
Two years before current fiscal year, writeoff	0.0	0.0
Three years before current fiscal year, writeoff	0.0	0.0
Four years before current fiscal year, writeoff	0.0	0.0
Five years before current fiscal year, writeoff	0.0	0.0
Revolving Loans Amortized Cost Basis, Writeoff	0.0	0.0
Charge-offs	0.0	0.0
Other CRE - non-owner occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	0.0	0.0
Year before current fiscal year, writeoff	0.0	0.0
Two years before current fiscal year, writeoff	0.0	10.9
Three years before current fiscal year, writeoff	15.0	3.6
Four years before current fiscal year, writeoff	12.6	0.0
Five years before current fiscal year, writeoff	0.1	0.0
Revolving Loans Amortized Cost Basis, Writeoff	0.0	0.0
Charge-offs	27.7	14.5
Residential
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	0.0	0.0
Year before current fiscal year, writeoff	0.0	0.0
Two years before current fiscal year, writeoff	0.0	0.0
Three years before current fiscal year, writeoff	0.0	0.0
Four years before current fiscal year, writeoff	0.0	0.0
Five years before current fiscal year, writeoff	0.0	0.0
Revolving Loans Amortized Cost Basis, Writeoff	0.0	0.0
Charge-offs	0.0	0.0
Residential EBO
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	0.0	0.0
Year before current fiscal year, writeoff	0.0	0.0
Two years before current fiscal year, writeoff	0.0	0.0
Three years before current fiscal year, writeoff	0.0	0.0
Four years before current fiscal year, writeoff	0.0	0.0
Five years before current fiscal year, writeoff	0.0	0.0
Revolving Loans Amortized Cost Basis, Writeoff	0.0	0.0
Charge-offs	0.0	0.0
Construction and land development
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	0.0	0.0
Year before current fiscal year, writeoff	0.0	0.0
Two years before current fiscal year, writeoff	0.0	0.0
Three years before current fiscal year, writeoff	0.0	0.0
Four years before current fiscal year, writeoff	0.0	0.0
Five years before current fiscal year, writeoff	0.0	0.0
Revolving Loans Amortized Cost Basis, Writeoff	0.0	0.0
Charge-offs	0.0	0.0
Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Current fiscal year, writeoff	0.0	0.0
Year before current fiscal year, writeoff	0.0	0.0
Two years before current fiscal year, writeoff	0.0	0.0
Three years before current fiscal year, writeoff	0.0	0.0
Four years before current fiscal year, writeoff	0.0	0.0
Five years before current fiscal year, writeoff	0.5	0.0
Revolving Loans Amortized Cost Basis, Writeoff	0.1	0.0
Charge-offs	$ 0.6	$ 0.0

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/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph c
-Publisher SEC

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Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6

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