Derivatives and Hedging Activities - Schedule of Notional Amounts of Outstanding Derivative Positions (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	May 01, 2020 USD ($)
Derivative [Line Items]
Interest Rate Cash Flow Hedge Derivative at Fair Value, Net	$ 0.0
Document Period End Date	Mar. 31, 2021
Derivative Assets (included in other assets on the consolidated balance sheets):
Derivative Asset, Notional Amount	$ 1,050.7	$ 901.6
Derivative Asset, Estimated Fair Value	49.4	55.3
Derivative Liabilities (included in accounts payable and accrued expenses on the consolidated balance sheets):
Derivative Liabilities, Notional Amount	941.4	1,014.1
Derivative Liabilities, Estimated Fair Value	47.0	53.3
Interest rate swap contracts
Derivative Assets (included in other assets on the consolidated balance sheets):
Derivative Asset, Notional Amount	87.6	87.6
Derivative Asset, Estimated Fair Value	0.2	0.2
Not Designated as Hedging Instrument | Interest rate swap contracts
Derivative Assets (included in other assets on the consolidated balance sheets):
Derivative Asset, Notional Amount	853.8	799.7
Derivative Asset, Estimated Fair Value	46.8	52.0
Derivative Liabilities (included in accounts payable and accrued expenses on the consolidated balance sheets):
Derivative Liabilities, Notional Amount	853.8	799.7
Derivative Liabilities, Estimated Fair Value	46.8	52.0
Not Designated as Hedging Instrument | Interest rate lock commitments
Derivative Assets (included in other assets on the consolidated balance sheets):
Derivative Asset, Notional Amount	90.9	101.9
Derivative Asset, Estimated Fair Value	1.1	3.3
Not Designated as Hedging Instrument | Forward loan sales contracts
Derivative Assets (included in other assets on the consolidated balance sheets):
Derivative Asset, Notional Amount	106.0	0.0
Derivative, Fair Value, Net	1.5	0.0
Derivative Liabilities (included in accounts payable and accrued expenses on the consolidated balance sheets):
Derivative Liabilities, Notional Amount	0.0	126.8
Derivative Liabilities, Estimated Fair Value	$ 0.0	$ 1.1
Interest rate swap contracts
Derivative [Line Items]
Derivative, Notional Amount, Contract 1			$ 46.4
Derivative, Notional Amount, Contract 2			36.1
Derivative, Notional Amount			$ 5.1
Derivative, Fixed Interest Rate, Contract 1			0.0040
Derivatives, Fixed Interest Rate, Contract 2			0.0034
Derivatives, Fixed Interest Rate, Contract 3			0.0040