Selected Quarterly Financial Data (unaudited) (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Net income	$ 7,416	$ 3,737	$ 4,630	$ 3,559	$ 991	$ 3,560	$ 2,572	$ 1,881	$ 19,342	$ 9,004
Earnings Per Share, Basic and Diluted	$ 0.44				$ 0.06
Interest income	$ 13,103	$ 12,965	$ 12,981	$ 13,021	$ 13,305	$ 12,506	$ 12,193	$ 12,086	52,070	50,090
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount					$ 2,500				0	$ 2,487
Equity Securities, FV-NI, Realized Gain	3,600								$ 3,400
Compensation expense	$ 1,000