Computation of Basic and Diluted Net Income (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Numerator:
Net income (loss)	$ (2,520)	$ 1,629	$ (8,202)	$ (2,114)	$ (522)
Denominator:
Weighted-average common shares (in thousands) - basic	20,936	20,491	20,766	18,519
Effect of contingent purchase price obligations		256
Weighted-average common shares (in thousands) - diluted	20,936	21,143	20,766	18,519
Basic and diluted net income (loss) per share	$ (0.12)	$ 0.08	$ (0.39)	$ (0.11)
Restricted Stock
Denominator:
Effect of restricted share units		385
Restricted Share Units
Denominator:
Effect of restricted share units		11