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, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share Basic And Diluted [Abstract]
Net income (loss)	$ 2,338	$ (35,592)	$ (16,279)	$ 1,424	$ (33,254)	$ (14,855)
Denominator:
Weighted average common shares outstanding, basic	84,123,530		85,359,998		84,220,649	85,728,820
Basic earnings per share:
Net income (loss) per share	$ 0.03		$ (0.19)		$ (0.39)	$ (0.17)
Denominator:
Weighted average common shares outstanding, basic	84,123,530		85,359,998		84,220,649	85,728,820
Dilutive securities:
Stock options and restricted stock units	545,720
Weighted average common shares outstanding, diluted	84,669,250		85,359,998		84,220,649	85,728,820
Diluted earnings per share:
Net income (loss) per share	$ 0.03		$ (0.19)		$ (0.39)	$ (0.17)