Earnings per Share - Summary of Computation for Basic and Diluted Net Earnings (Loss) per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator
Numerator for basic and diluted earnings (loss) per share		$ 51,386	$ 4,996	$ 2,175	$ (2,356)	$ 4,695	$ 1,043	$ (2,226)	$ (5,539)	$ 56,201	$ (2,027)	$ (6,515)
Denominator
Basic weighted average common shares outstanding		166,744	166,375	165,703	165,429	163,952	163,119	162,734	160,446	166,066	162,574	157,407
Dilutive effects of stock options and share-based awards issuable under equity compensation plans										4,089
Diluted weighted average common shares outstanding		171,412	169,655	169,228	165,429	171,238	168,503	162,734	160,446	170,155	162,574	157,407
Computation of:
Basic net earnings (loss) per share										$ 0.34	$ (0.01)	$ (0.04)
Diluted net earnings (loss) per share										$ 0.33	$ (0.01)	$ (0.04)
Anti-dilutive common stock equivalents	[1]									7,092	17,103	17,147

[1] These common stock equivalents were outstanding for the period but were not included in the computation of diluted EPS for those periods as their inclusion would have had an anti-dilutive effect.