The Company and Significant Accounting Policies - Reconciliation of Basic and Diluted Income (Loss) Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share Basic And Diluted [Abstract]
Net income	$ 3,495	$ 5,717	$ 6,113	$ 7,987
Denominator:
Weighted average common shares outstanding, basic	90,354,982	89,134,412	90,296,057	89,015,934
Basic earnings per share:
Net income per share, basic	$ 0.04	$ 0.06	$ 0.07	$ 0.09
Denominator:
Weighted average common shares outstanding, basic	90,354,982	89,134,412	90,296,057	89,015,934
Dilutive securities:
Stock options and restricted stock units	1,678,129	2,006,184	1,601,093	2,020,419
Weighted average common shares outstanding, diluted	92,033,111	91,140,596	91,897,150	91,036,353
Diluted earnings per share:
Net income per share, diluted	$ 0.04	$ 0.06	$ 0.07	$ 0.09