Quarterly Financial Information - Summary of Condensed Consolidated Statements of Operations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ 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
Income Statement [Abstract]
Revenue	$ 25,028	$ 26,435	$ 28,873	$ 26,265	$ 25,595	$ 24,535	$ 23,055	$ 22,731	$ 106,601	$ 95,916
Gross profit	4,916	4,873	5,232	5,449	4,764	3,963	4,265	3,535	20,470	16,527
Income (loss) from operations	1,297	1,387	1,871	1,876	1,288	723	670	(197)	6,431	2,484
Net income (loss)	$ 1,140	$ 1,245	$ 1,885	$ 1,823	$ 1,396	$ 691	$ 651	$ (393)	$ 6,093	$ 2,345
Basic income (loss) per share	$ 0.09	$ 0.10	$ 0.16	$ 0.15	$ 0.12	$ 0.06	$ 0.06	$ (0.03)	$ 0.51	$ 0.20
Diluted income (loss) per share	$ 0.09	$ 0.10	$ 0.15	$ 0.15	$ 0.12	$ 0.06	$ 0.06	$ (0.03)	$ 0.49	$ 0.20
Shares used in calculation of income (loss) per share:
Basic	12,047	11,959	11,856	11,778	11,735	11,655	11,510	11,390	11,938	11,574
Diluted	12,649	12,466	12,295	12,057	11,945	11,832	11,715	11,390	12,419	11,788