Computation of Earnings per Share - Summary of net income per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net income	$ 1,573	$ 2,197	$ 3,643	$ 2,788
Shares outstanding:
Weighted-average common shares outstanding (in shares)	22,847	22,930	22,934	22,888
Additional dilutive common stock equivalents (in shares)	92	81	62	61
Diluted shares outstanding (in shares)	22,939	23,011	22,996	22,949
Net income per share - basic (in dollars per share)	$ 0.07	$ 0.10	$ 0.16	$ 0.12
Net income per share - diluted (in dollars per share)	$ 0.07	$ 0.10	$ 0.16	$ 0.12