Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Earnings Per Share [Abstract]
Net loss		$ (105,025)	$ (167,250)
Weighted-average common shares outstanding - basic		87,253	79,454
Effect of dilutive securities*	[1]	0	0
Weighted-average common shares outstanding - diluted		87,253	79,454
Net loss per share - basic and diluted		$ (1.20)	$ (2.10)

[1] For the three months ended March 31, 2022 and 2021, stock options, RSAs, RSUs, and ESPP to purchase 11.3 million and 10.3 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 its 2024 Notes on diluted net earnings per share (“EPS”) 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, 2022 and March 31, 2021, respectively, the inclusion of the potential share settlement of the 2024 Notes was anti-dilutive. Accordingly, the potential conversion of 7,763,552 shares has been excluded from the computation of diluted net loss per share as of March 31, 2022 and March 31, 2021, respectively.