Unaudited Supplementary Quarterly Financial Information - Unaudited Supplementary Quarterly Financial Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2016		Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015		Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$ 29,774		$ 30,826	$ 34,024	$ 31,898	$ 28,415		$ 31,184	$ 30,527	$ 26,578	$ 126,522	$ 116,704	$ 112,989
Gross profit	11,978		10,640	12,814	10,750	9,776		11,756	10,413	7,645	46,182	39,590	41,366
Net (loss) income	$ (3,427)	[1]	$ 43	$ 1,313	$ (763)	$ (4,641)	[1]	$ 1,027	$ 494	$ (940)	$ (2,834)	$ (4,060)	$ 4,064
Basic (loss) income per share	$ (0.28)		$ 0.00	$ 0.11	$ (0.06)	$ (0.40)		$ 0.09	$ 0.04	$ (0.08)	$ (0.23)	$ (0.35)	$ 0.37
Diluted (loss) income per share	$ (0.28)		$ 0.00	$ 0.09	$ (0.06)	$ (0.40)		$ 0.08	$ 0.04	$ (0.08)	$ (0.23)	$ (0.35)	$ 0.31

[1] The Company's fourth quarter 2016 and 2015 net loss includes $3.7 million and $3.6 million, respectively, of expense associated with the increase to the valuation allowance applied against the carrying value of its deferred tax attributes and the impairment of certain state net operating loss carryforwards.