Derivatives and Hedging Activities - Schedule of Master Netting Arrangements (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Derivative Asset [Abstract]
Derivative Asset, Fair Value, Gross Asset	$ 45.2	$ 28.1
Derivative Asset, Fair Value, Gross Liability	0.0	0.0
Derivative Asset, Total	45.2	28.1
Derivative, Collateral, Obligation to Return Securities	0.0	0.0
Derivative, Collateral, Obligation to Return Cash	45.1	8.0
Derivative Asset, Fair Value, Amount Offset Against Collateral, Total	0.1	20.1
Offsetting Derivative Liabilities [Abstract]
Derivative Liability, Fair Value, Gross Liability	159.6	18.2
Derivative Liability, Fair Value, Gross Asset	0.0	0.0
Derivative Liability, Total	159.6	18.2
Derivative, Collateral, Right to Reclaim Securities	0.0	0.0
Derivative, Collateral, Right to Reclaim Cash	0.0	0.0
Derivative Liability, Fair Value, Amount Offset Against Collateral, Total	159.6	18.2
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral [Abstract]
Securities Sold under Agreements to Repurchase, Gross	1,052.9	1,051.1
Securities Sold under Agreements to Repurchase, Asset	0.0	0.0
Securities Sold under Agreements to Repurchase, Total	1,052.9	1,051.1
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	0.0	0.0
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Cash	1,052.9	1,051.1
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral, Total	0.0	0.0
Offsetting Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned [Abstract]
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Gross	1,212.5	1,069.3
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Asset	0.0	0.0
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Total	1,212.5	1,069.3
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Collateral, Right to Reclaim Securities	0.0	0.0
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Collateral, Right to Reclaim Cash	1,052.9	1,051.1
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Amount Offset Against Collateral, Total	159.6	18.2
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
Collateral Pledged
Offsetting Derivative Liabilities [Abstract]
Derivative, Collateral, Right to Reclaim Securities	0.0
Offsetting Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned [Abstract]
Derivative, Fair Value, Net	0.0
Interest Rate Swap [Member]
Derivative Asset [Abstract]
Derivative Asset, Fair Value, Gross Asset	45.1	26.3
Derivative Asset, Fair Value, Gross Liability	0.0	0.0
Derivative Asset, Total	45.1	26.3
Derivative, Collateral, Obligation to Return Securities	0.0	0.0
Derivative, Collateral, Obligation to Return Cash	45.1	8.0
Derivative Asset, Fair Value, Amount Offset Against Collateral, Total	0.0	18.3
Offsetting Derivative Liabilities [Abstract]
Derivative Liability, Fair Value, Gross Liability	159.6	18.2
Derivative Liability, Fair Value, Gross Asset	0.0	0.0
Derivative Liability, Total	159.6	18.2
Derivative, Collateral, Right to Reclaim Securities	0.0	0.0
Derivative, Collateral, Right to Reclaim Cash	0.0	0.0
Derivative Liability, Fair Value, Amount Offset Against Collateral, Total	159.6	18.2
Interest Rate Swap [Member] | Not Designated as Hedging Instrument
Offsetting Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned [Abstract]
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
Interest Rate Swap [Member] | Designated as Hedging Instrument
Offsetting Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned [Abstract]
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
Mortgage related derivatives
Derivative Asset [Abstract]
Derivative Asset, Fair Value, Gross Asset	0.1	1.8
Derivative Asset, Fair Value, Gross Liability	0.0	0.0
Derivative Asset, Total	0.1	1.8
Derivative, Collateral, Obligation to Return Securities	0.0	0.0
Derivative, Collateral, Obligation to Return Cash	0.0	0.0
Derivative Asset, Fair Value, Amount Offset Against Collateral, Total	0.1	1.8
Offsetting Derivative Liabilities [Abstract]
Derivative Liability, Fair Value, Gross Liability	0.0
Derivative Liability, Fair Value, Gross Asset	0.0
Derivative Liability, Total	0.0
Derivative, Collateral, Right to Reclaim Securities	0.0
Derivative, Collateral, Right to Reclaim Cash	0.0
Derivative Liability, Fair Value, Amount Offset Against Collateral, Total	0.0
Forward Contracts [Member] | Not Designated as Hedging Instrument
Offsetting Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned [Abstract]
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
Derivative, Fair Value, Net	0.1	0.0
Interest Rate Collars | Designated as Hedging Instrument
Offsetting Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned [Abstract]
Derivative Liability, Notional Amount	300.0	0.0
Derivative Liabilities, Estimated Fair Value	5.4	0.0
Risk Participation Agreements
Offsetting Derivative Liabilities [Abstract]
Derivative Liability, Fair Value, Gross Liability	0.0
Derivative Liability, Fair Value, Gross Asset	0.0
Derivative Liability, Total	0.0
Derivative, Collateral, Right to Reclaim Securities	0.0
Derivative, Collateral, Right to Reclaim Cash	0.0
Derivative Liability, Fair Value, Amount Offset Against Collateral, Total	0.0
Risk Participation Agreements | Not Designated as Hedging Instrument
Offsetting Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned [Abstract]
Derivative Liability, Notional Amount	106.1	0.0
Derivative Liabilities, Estimated Fair Value	0.0	0.0
Interest Rate Lock Commitments [Member] | Not Designated as Hedging Instrument
Offsetting Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned [Abstract]
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