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		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net income	$ 59,000	$ 40,766	$ 140,835	$ 88,997
Denominator:
Weighted-average shares outstanding - basic (in shares)	197,815	191,319	197,216	190,731
Weighted-average shares outstanding - diluted (in shares)	202,273	201,453	202,348	200,843
Net income per share - basic (in dollars per share)	$ 0.30	$ 0.21	$ 0.71	$ 0.47
Net income per share - diluted (in dollars per share)	$ 0.29	$ 0.20	$ 0.70	$ 0.44
Common stock options
Denominator:
Potentially dilutive securities (in shares)	297	538	323	647
RSUs
Denominator:
Potentially dilutive securities (in shares)	2,913	3,613	3,375	3,791
ESPP obligations
Denominator:
Potentially dilutive securities (in shares)	0	11	0	0
2022 Warrants | Warrants
Denominator:
Potentially dilutive securities (in shares)	602	2,462	610	2,260
Partial settlement of 2022 Warrants (in shares)	0	0	102	0
2022 Notes | Convertible senior notes
Denominator:
Potentially dilutive securities (in shares)	567	3,500	571	3,370
Potentially dilutive securities (in shares)	80	10	151	44