Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Net loss		$ (167,250)	$ (17,492)
Weighted-average common shares outstanding - basic		79,454	76,432
Effect of dilutive securities*	[1]	0	0
Weighted-average common shares outstanding - diluted		79,454	76,432
Net loss per share - basic and diluted		$ (2.10)	$ (0.23)

[1] For the three months ended March 31, 2021 and 2020, stock options, RSAs, RSUs, and ESPP to purchase 10.3 million and 10.5 million shares of the Company’s common stock, respectively, were excluded from the diluted net loss per share calculation as their effect would have been anti-dilutive. The Company accounts for the effect of the 2024 Notes on diluted net earnings per share using the if-converted method as this obligation may be settled in cash or shares at the Company’s option. The effect of potential share settlement is included in the diluted EPS calculation if the effect is more dilutive. During the three months ended March 31, 2021, the inclusion of the potential share settlement of the 2024 was anti-dilutive.