Loans and Leases - Modifications to Borrowers Experiencing Financial Difficulty (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0.0	$ 0.0
% of Total Class	0.00%	0.00%
Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 83.0	$ 96.0
% of Total Class	0.10%	0.20%
Principal Forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0.0	$ 0.0
% of Total Class	0.00%	0.00%
Payment Deferrals
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0.0	$ 4.0
% of Total Class	0.00%	0.00%
Combination - Term Extension and Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 1.0	$ 2.0
% of Total Class	0.00%	0.00%
Combination - Principal Forgiveness and Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0.0	$ 18.0
% of Total Class	0.00%	0.00%
Commercial: \| Commercial and industrial \| Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 64.0	$ 63.0
% of Total Class	0.20%	0.20%
Weighted average life of loans	1 year 4 months 24 days	1 year
Commercial: \| Commercial and industrial \| Combination - Principal Forgiveness and Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0.0	$ 18.0
% of Total Class	0.00%	0.10%
Weighted average life of loans		6 years 2 months 12 days
Decrease from loan modification		$ 2.0
Commercial: \| Commercial real estate \| Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 19.0	$ 32.0
% of Total Class	0.10%	0.20%
Weighted average life of loans	9 months 18 days	7 months 6 days
Consumer: \| Consumer Real Estate \| Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0.0	$ 0.0
% of Total Class	0.00%	0.00%
Consumer: \| Consumer Real Estate \| Interest Rate Reduction \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	9.95%
Consumer: \| Consumer Real Estate \| Interest Rate Reduction \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	6.75%
Consumer: \| Consumer Real Estate \| Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0.0	$ 1.0
% of Total Class	0.00%	0.00%
Weighted average life of loans		14 years 10 months 24 days
Consumer: \| Consumer Real Estate \| Principal Forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0.0	$ 0.0
% of Total Class	0.00%	0.00%
Decrease from loan modification	$ 1.0
Consumer: \| Consumer Real Estate \| Payment Deferrals
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0.0	$ 4.0
% of Total Class	0.00%	0.00%
Weighted average life of loans		11 months
Consumer: \| Consumer Real Estate \| Combination - Term Extension and Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 1.0	$ 2.0
% of Total Class	0.00%	0.00%
Weighted average life of loans	18 years 9 months 18 days	8 years 9 months 18 days
Consumer: \| Consumer Real Estate \| Combination - Term Extension and Interest Rate Reduction \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	6.43%	5.00%
Consumer: \| Consumer Real Estate \| Combination - Term Extension and Interest Rate Reduction \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	3.69%	4.90%
Consumer: \| Credit Card and Other \| Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0.0	$ 0.0
% of Total Class	0.00%	0.00%
Consumer: \| Credit Card and Other \| Interest Rate Reduction \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	20.50%
Consumer: \| Credit Card and Other \| Interest Rate Reduction \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	0.00%

Amount of increase (decrease) in amortized cost excluding accrued interest, of financing receivable modified for debtor experiencing financial difficulty.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-42

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
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-Section 50
-Paragraph 42
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-42

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
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-Section 50
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-42

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
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-URI https://asc.fasb.org//1943274/2147481933/310-10-55-12A

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 33
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-URI https://asc.fasb.org//1943274/2147481962/310-10-50-33

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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-34

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