Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Line Items]
Operating leases rental expense	$ 1,000	$ 1,100
Minimum [Member]
Commitments and Contingencies Disclosure [Line Items]
Lease expiration period	4 months
Lease expiration period, renewal option	1 year
Maximum [Member]
Commitments and Contingencies Disclosure [Line Items]
Lease expiration period	23 years
Lease expiration period, renewal option	5 years
Commitments to extend credit on standby letters of credit [Member] | Commitments to extend credit [Member]
Commitments and Contingencies Disclosure [Line Items]
Contract amount	$ 6,656	$ 6,666