Selected Quarterly Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Selected Quarterly Data [Abstract]
Revenues, net	$ 16,421	$ 18,060	$ 25,045	$ 21,663	$ 18,810	$ 18,096	$ 24,199	$ 24,882	$ 81,189	$ 85,987	$ 76,070
Gross profit	6,651	7,097	10,495	8,792	7,469	7,139	9,695	9,914	33,035	34,217	29,118
Net income	$ 787	$ 3,653	$ 5,040	$ 3,558	$ 1,408	$ 4,303	$ 3,782	$ 5,015	$ 13,038	$ 14,508	$ 18,808
Net income per share - basic	$ 0.05	$ 0.20	$ 0.28	$ 0.20	$ 0.08	$ 0.23	$ 0.20	$ 0.27	$ 0.74	$ 0.78	$ 1.06
Net income per share - diluted	$ 0.05	$ 0.20	$ 0.27	$ 0.19	$ 0.08	$ 0.23	$ 0.20	$ 0.26	$ 0.73	$ 0.77	$ 1.02