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
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share Basic And Diluted [Abstract]
Net income (loss)	$ (1,808)	$ 2,618
Denominator:
Weighted average common shares outstanding, basic	90,319,092	90,236,476
Basic earnings per share:
Net income (loss) per share	$ (0.02)	$ 0.03
Denominator:
Weighted average common shares outstanding, basic	90,319,092	90,236,476
Dilutive securities:
Stock options and restricted stock units		1,524,055
Weighted average common shares outstanding, diluted	90,319,092	91,760,531
Diluted earnings per share:
Net income (loss) per share	$ (0.02)	$ 0.03