Earnings Per Share (Schedule of Earnings per Share) (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, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Basic Earnings Per Share
Net income													$ 18,864	$ 12,315	$ 13,241
Weighted-Average Shares number of common shares, basic													8,394,195	7,360,066	7,391,681
Earnings per share, basic	$ 0.62	$ 0.63	$ 0.49	$ 0.51	$ 0.20	$ 0.51	$ 0.53	$ 0.44	$ 0.44	$ 0.48	$ 0.56	$ 0.32	$ 2.25	$ 1.67	$ 1.79
Net income available and assumed conversions													$ 18,864	$ 12,315	$ 13,241
Weighted-Average Shares, effect of dilutive securities stock option													149,302	141,993	147,157
Weighted-Average Shares income available to common stockholders and assumed conversions, diluted													8,543,497	7,502,059	7,538,838
Earnings per share, diluted	$ 0.61	$ 0.62	$ 0.48	$ 0.50	$ 0.19	$ 0.50	$ 0.52	$ 0.43	$ 0.43	$ 0.47	$ 0.55	$ 0.31	$ 2.21	$ 1.64	$ 1.76