Derivatives and Hedging Activities (Derivative Positions for Interest Rate Swaps which Qualify as Hedges) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Derivative, Cap Interest Rate	3.02%
Derivative, Floor Interest Rate	2.51%
Amortization Of Deferred Hedge Gains Losses	$ 231,000	$ 244,000	$ 244,000
Notional amount of fair value hedged derivative	$ 0	$ 0	$ 0
Interest rate swaps on borrowings [Member]
Derivatives, Fair Value [Line Items]
Derivative, Average Remaining Maturity	3 years 2 months 4 days	3 years 4 months 13 days
Derivative, Average Variable Interest Rate	2.74%	1.54%
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Notional Amount	$ 75,000,000	$ 100,000,000
Fair Value	$ 2,282,000	$ 1,616,000
Derivative, Average Fixed Interest Rate	1.53%	1.89%
Interest rate swaps on loans [Member]
Derivatives, Fair Value [Line Items]
Derivative, Average Remaining Maturity	4 years 6 months 7 days
Derivative, Average Variable Interest Rate	2.57%
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Notional Amount	$ 250,000,000
Fair Value	$ 2,938,000
Derivative, Average Fixed Interest Rate	2.67%
Interest rate collars on loans [Member]
Derivatives, Fair Value [Line Items]
Derivative, Average Remaining Maturity	4 years 2 months 1 day
Derivative, Average Variable Interest Rate	2.47%
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Notional Amount	$ 250,000,000
Fair Value	3,344,000
Interest Rate Swap [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Notional Amount	575,000,000	$ 100,000,000
Fair Value	$ 8,564,000	$ 1,616,000