Derivatives and Hedging Activities - Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Derivative [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax	$ 0.0	$ 0.3
Financial Instruments	0.0		$ 0.0
Derivative Asset, Notional Amount	1,140.8		1,201.0
Derivative Asset, Estimated Fair Value	27.1		26.6
Derivative Liability, Notional Amount	1,189.3		1,269.5
Derivative Liabilities, Estimated Fair Value	76.8		77.3
Collateral Pledged
Derivative [Line Items]
Derivative, Fair Value, Net	0.0
Financial Instruments	0.0
Not Designated as Hedging Instrument
Derivative [Line Items]
Amount of net fee income recognized in other noninterest income	0.0	0.0
Interest Rate Swap | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Asset, Notional Amount	1,126.0		1,199.0
Derivative Asset, Estimated Fair Value	27.0		26.6
Derivative Liability, Notional Amount	1,126.0		1,204.9
Derivative Liabilities, Estimated Fair Value	76.8		77.3
Risk Participation Agreements | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Liability, Notional Amount	63.3		64.6
Derivative Liabilities, Estimated Fair Value	0.0		0.0
Forward Contracts | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative, Fair Value, Net	0.0		0.0
Derivative Asset, Notional Amount	8.3		1.0
Interest Rate Lock Commitments | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Asset, Notional Amount	6.5		1.0
Derivative Asset, Estimated Fair Value	0.1		$ 0.0
Cash Flow Hedging [Member] | Interest Rate Swap | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax	$ 0.0	$ (1.0)