Quarterly Results of Operations - Quarterly Consolidated Statement of Operations Data (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	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 16,570	$ 14,313	$ 16,223	$ 16,287	$ 13,619	$ 12,051	$ 11,831	$ 15,436	$ 63,393	$ 52,937	$ 47,470
Gross profit	16,477	14,196	16,108	16,172	13,484	11,947	11,730	15,316
Operating income (Loss)	1,289	1,283	2,217	(70)	1,194	1,702	117	2,954	4,719	5,967	3,604
Income before provision for income taxes	1,082	1,199	2,263	(95)	1,439	1,672	261	2,947	4,449	6,319	3,672
Benefit (provision) for income taxes	56	(1,015)	(668)	36	(422)	(599)	(92)	(1,083)	(1,591)	(2,196)	36,483
Net income	$ 1,138	$ 184	$ 1,595	$ (59)	$ 1,017	$ 1,073	$ 169	$ 1,864	$ 2,858	$ 4,123	$ 40,155
Basic net income (loss) per share (in dollars per share)	$ 0.04	$ 0.01	$ 0.06	$ 0.00	$ 0.04	$ 0.04	$ 0.01	$ 0.07	$ 0.10	$ 0.15	$ 1.42
Shares used in calculating basic net income (loss) per share (in shares)	28,305	28,190	28,070	27,818	27,733	28,505	28,383	28,370	28,097	28,246	28,190
Diluted net income (loss) per share (in dollars per shares)	$ 0.04	$ 0.01	$ 0.06	$ 0.00	$ 0.04	$ 0.04	$ 0.01	$ 0.06	$ 0.10	$ 0.14	$ 1.37
Shares used in calculating diluted net income (loss) per share (in shares)	29,322	29,134	28,906	27,818	28,430	29,351	29,210	29,382	29,015	29,144	29,338