Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended				6 Months Ended
		Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share [Abstract]
Net loss		$ (231,481)	$ (105,025)	$ (81,405)	$ (167,250)	$ (336,506)	$ (248,655)
Weighted-average common shares outstanding - basic		87,511		79,746		87,383	79,601
Effect of dilutive securities*	[1]	0		0		0	0
Weighted-average common shares outstanding - diluted		87,511		79,746		87,383	79,601
Net loss per share - basic and diluted		$ (2.65)		$ (1.02)		$ (3.85)	$ (3.12)
Net loss per share - basic and diluted		$ (2.65)		$ (1.02)		$ (3.85)	$ (3.12)

[1] For the three and six months ended June 30, 2022 and 2021, stock options, RSAs, RSUs, and ESPP to purchase 11.3 million and 9.8 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 and six months ended June 30, 2022 and June 30, 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 June 30, 2022 and June 30, 2021, respectively.