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Derivatives and Hedging Activities - Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2024 | Mar. 31, 2023 | Dec. 31, 2023
Derivative [Line Items] |  |  |
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net | $ 13.2 |  |
Derivative Instruments and Hedges, Assets | 193.6 |  | $ 193.3
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease) | 6.4 |  | 6.7
Financial Instruments | 0.0 |  | 0.0
Derivative Asset, Notional Amount | 1,543.1 |  | 2,144.7
Derivative Asset, Estimated Fair Value | 44.2 |  | 37.4
Derivative Liability, Notional Amount | 2,793.9 |  | 2,295.7
Derivative Liabilities, Estimated Fair Value | 156.6 |  | 127.3
Collateral Pledged |  |  |
Derivative [Line Items] |  |  |
Derivative, Fair Value, Net | 1.1 |  |
Financial Instruments | 0.2 |  |
Not Designated as Hedging Instrument |  |  |
Derivative [Line Items] |  |  |
Amount of net fee income recognized in other non-interest income | 0.0 |  |
Amount of net gains recognized in mortgage banking revenues | 0.1 | $ 0.1 |
Interest Rate Swap |  |  |
Derivative [Line Items] |  |  |
Derivative Instruments and Hedges, Assets | 850.0 |  |
Interest Rate Swap | Designated as Hedging Instrument [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Asset, Notional Amount | 0.0 |  | 550.0
Derivative Asset, Estimated Fair Value | 0.0 |  | 3.0
Derivative Liability, Notional Amount | 850.0 |  | 300.0
Derivative Liabilities, Estimated Fair Value | 12.3 |  | 2.4
Interest Rate Swap | Not Designated as Hedging Instrument |  |  |
Derivative [Line Items] |  |  |
Derivative Asset, Notional Amount | 1,535.6 |  | 1,589.0
Derivative Asset, Estimated Fair Value | 44.1 |  | 34.3
Derivative Liability, Notional Amount | 1,535.6 |  | 1,589.0
Derivative Liabilities, Estimated Fair Value | 139.8 |  | 121.1
Risk Participation Agreements |  |  |
Derivative [Line Items] |  |  |
Financial Instruments |  |  | 0.0
Risk Participation Agreements | Not Designated as Hedging Instrument |  |  |
Derivative [Line Items] |  |  |
Derivative Liability, Notional Amount | 99.7 |  | 101.1
Derivative Liabilities, Estimated Fair Value | 0.0 |  | 0.1
Forward Contracts |  |  |
Derivative [Line Items] |  |  |
Financial Instruments |  |  | 0.0
Forward Contracts | Not Designated as Hedging Instrument |  |  |
Derivative [Line Items] |  |  |
Derivative, Fair Value, Net | 0.0 |  | 0.0
Derivative Asset, Notional Amount | 0.0 |  | 0.0
Derivative Liability, Notional Amount | 8.6 |  | 5.6
Derivative Liabilities, Estimated Fair Value | 0.0 |  | 0.1
Interest Rate Lock Commitments | Not Designated as Hedging Instrument |  |  |
Derivative [Line Items] |  |  |
Derivative Asset, Notional Amount | 7.5 |  | 5.7
Derivative Asset, Estimated Fair Value | 0.1 |  | 0.1
Derivative Liability, Notional Amount | 0.0 |  | 0.0
Derivative Liabilities, Estimated Fair Value | 0.0 |  | 0.0
Interest Rate Collars |  |  |
Derivative [Line Items] |  |  |
Derivative Instruments and Hedges, Assets | 300.0 |  |
Interest Rate Collars | Designated as Hedging Instrument [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Liability, Notional Amount | 300.0 |  | 300.0
Derivative Liabilities, Estimated Fair Value | 4.5 |  | $ 3.6
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 | $ 17.4 | $ (9.5) |

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