Derivative Financial Instruments (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Forward Commitments to Sell Mortgage Loans [Member]
Derivative [Abstract]
Aggregate notional amount of derivatives	$ 698,600,000	$ 345,000,000
Gain (loss) reported as a component of other assets	(9,500,000)	3,000,000
Interest Rate Lock Commitments [Member]
Derivative [Abstract]
Aggregate notional amount of derivatives	499,400,000	174,300,000
Gain (loss) reported as a component of other assets	8,000,000	1,800,000
Interest Rate Swap [Member] | Dealer Counterparties [Member]
Derivative [Abstract]
Aggregate notional amount of derivatives	30,800,000	30,900,000
Interest Rate Swap [Member] | Commercial Borrower [Member]
Derivative [Abstract]
Aggregate notional amount of derivatives	30,800,000	30,900,000
Interest Rate Swap [Member] | Other Assets [Member] | Commercial Borrower [Member]
Derivative [Abstract]
Derivative asset, notional amount	3,800,000	680,000
Interest Rate Swap [Member] | Other Liabilities [Member] | Dealer Counterparties [Member]
Derivative [Abstract]
Derivative Liability, Notional Amount	3,800,000	680,000
Fair Value Hedging [Member]
Derivative [Abstract]
Derivative fair value	$ 4,100,000	$ 710,000