Quarterly Financial Information (Unaudited) - 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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenue	$ 15,366	$ 14,641	$ 14,180	$ 15,096	$ 16,839	$ 16,694	$ 19,203	$ 20,678	$ 59,283	$ 73,414
Gross profit	2,650	2,632	2,423	2,391	3,690	3,359	3,261	5,200	10,096	15,510
Income (loss) from operations	(1,377)	(1,129)	(3,929)	(2,879)	(5,603)	(2,132)	(3,718)	(2,478)	(9,314)	(13,931)
Net income (loss)	$ (1,360)	$ (1,107)	$ (3,868)	$ (2,846)	$ (5,533)	$ (2,087)	$ (3,683)	$ (2,434)	$ (9,181)	$ (13,737)
Basic income (loss) per share	$ (0.10)	$ (0.09)	$ (0.30)	$ (0.22)	$ (0.43)	$ (0.16)	$ (0.29)	$ (0.19)	$ (0.71)	$ (1.08)
Diluted income (loss) per share	$ (0.10)	$ (0.09)	$ (0.30)	$ (0.22)	$ (0.43)	$ (0.16)	$ (0.29)	$ (0.19)	$ (0.71)	$ (1.08)
Shares used in per share calculations:
Basic	12,997	12,934	12,855	12,795	12,755	12,721	12,697	12,673	12,896	12,712
Diluted	12,997	12,934	12,855	12,795	12,755	12,721	12,697	12,673	12,896	12,712