Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share
Net income	$ 4,291	$ 5,060	$ 8,764	$ 11,584
Income allotted to participating securities	(37)	(37)	(48)	(74)
Net income available to common shareholders	$ 4,254	$ 5,023	$ 8,716	$ 11,510
Weighted-average number of shares used in:
Basic earnings per share (in shares)	9,092,287	9,172,376	9,164,877	9,170,825
Dilutive common stock equivalents:
Stock options and restricted stock units (in shares)	46,848	104,304	63,544	123,502
Diluted earnings per share (in shares)	9,139,135	9,276,680	9,228,421	9,294,327
Net income per common share, basic (in dollars per share)	$ 0.47	$ 0.55	$ 0.95	$ 1.26
Net income per common share, diluted (in dollars per share)	$ 0.47	$ 0.54	$ 0.94	$ 1.24