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, 2019	Mar. 31, 2018
Earnings Per Share Basic And Diluted [Abstract]
Net income (loss)	$ 1,424	$ (1,808)
Denominator:
Weighted average common shares outstanding, basic	86,101,741	90,319,092
Basic earnings per share:
Net income (loss) per share	$ 0.02	$ (0.02)
Denominator:
Weighted average common shares outstanding, basic	86,101,741	90,319,092
Dilutive securities:
Stock options and restricted stock units	1,051,246
Weighted average common shares outstanding, diluted	87,152,987	90,319,092
Diluted earnings per share:
Net income (loss) per share	$ 0.02	$ (0.02)