Derivatives and Hedging Activities - Notional Amounts and Estimated Fair Values of Derivatives (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 2,290.7	$ 1,691.2
Derivative Assets, Estimated Fair Value	45.2	28.1
Derivative Liability, Notional Amount	2,449.0	1,103.9
Derivative Liabilities, Estimated Fair Value	159.6	18.2
Derivative Instruments and Hedges, Assets	191.9	695.6
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	8.1	(4.4)
Not Designated as Hedging Instrument | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	1,728.1	913.9
Derivative Assets, Estimated Fair Value	41.6	22.2
Derivative Liability, Notional Amount	1,728.1	913.9
Derivative Liabilities, Estimated Fair Value	153.9	18.1
Not Designated as Hedging Instrument | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	0.0	77.3
Derivative Assets, Estimated Fair Value	0.0	1.8
Derivative Liability, Notional Amount	14.8	0.0
Derivative Liabilities, Estimated Fair Value	0.0	0.0
Not Designated as Hedging Instrument | Forward Contracts [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	12.6	0.0
Derivative Liability, Notional Amount	0.0	102.4
Derivative Liabilities, Estimated Fair Value	0.0	0.0
Designated as Hedging Instrument | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	550.0	700.0
Derivative Assets, Estimated Fair Value	3.5	4.1
Derivative Liability, Notional Amount	300.0	87.6
Derivative Liabilities, Estimated Fair Value	$ 0.3	$ 0.1