Derivatives and Hedging Activities (Derivative Positions for Interest Rate Swaps which Qualify as Hedges) (Details) - USD ($)		3 Months Ended		12 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Amortization Of Deferred Hedge Gains Losses		$ 0
Change in Fair Value on Loans Held for Sale		(914,000)	$ 1,000		$ 1,000
Fair Value Hedges, Net		0		$ 0
Interest rate collars on loans [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Derivative, Notional Amount		$ 400,000,000		$ 400,000,000
Derivative, Average Remaining Maturity		3 years 4 months 28 days		3 years 7 months 28 days
Derivative, Average Variable Interest Rate		0.81%		1.76%
Fair Value	[1]	$ 25,573,000		$ 9,896,000
Derivative, Average Cap Interest Rate		2.73%		3.02%
Derivative, Average Floor Interest Rate		2.20%		2.51%
Interest rate swaps on loans [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Derivative, Notional Amount		$ 450,000,000		$ 450,000,000
Derivative, Average Remaining Maturity		3 years 4 months 28 days		3 years 7 months 28 days
Derivative, Average Variable Interest Rate		0.86%		1.76%
Derivative, Average Fixed Interest Rate		2.37%		2.37%
Fair Value	[1]	$ 31,701,000		$ 12,907,000
Interest rate swaps on borrowings [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Derivative, Notional Amount		$ 175,000,000		$ 75,000,000
Derivative, Average Remaining Maturity		2 years 2 months 12 days		2 years 2 months 4 days
Derivative, Average Variable Interest Rate		1.28%		1.90%
Derivative, Average Fixed Interest Rate		0.94%		1.53%
Fair Value	[1]	$ (1,790,000)		$ 140,000
Interest rate swaps
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Derivative, Notional Amount		1,025,000,000		925,000,000
Fair Value	[1]	$ 55,484,000		$ 22,943,000

[1] Beginning in 2020, the Company made an election to include accrued interest within fair value balances.