Net Income Per Share - Schedule of Basic and Diluted Net Income Per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net income	$ 82,440	$ 48,231
Denominator:
Weighted-average shares outstanding - basic (in shares)	196,624	190,163
Weighted-average shares outstanding - diluted (in shares)	202,268	199,938
Net income (loss) per share - basic (in dollars per share)	$ 0.42	$ 0.25
Net income (loss) per share - diluted (in dollars per share)	$ 0.41	$ 0.24
Common stock options
Denominator:
Potentially dilutive securities (in shares)	351	756
RSUs
Denominator:
Potentially dilutive securities (in shares)	3,671	3,751
2022 Warrants | Warrants
Denominator:
Potentially dilutive securities (in shares)	618	2,029
Partial settlement of 2022 Warrants (in shares)	206	0
2022 Notes | Convertible senior notes
Denominator:
Potentially dilutive securities (in shares)	748	3,229
Potentially dilutive securities (in shares)	50	10