Net Income Per Share - Computation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net income	$ 38,801	$ 39,926
Net income (loss) available to common stockholders, basic	38,801	39,926
Net income (loss) available to common stockholders, diluted	$ 39,911	$ 39,926
Denominator:
Weighted average number of common shares outstanding used in computing net income per share - basic (in shares)	157,821	160,967
Effect of dilutive securities:
Weighted average number of common shares outstanding used in computing net income per share - diluted (in shares)	189,540	162,347
Net income per share - basic (in dollars per share)	$ 0.25	$ 0.25
Net income per share - diluted (in dollars per share)	$ 0.21	$ 0.25
Employee stock options
Effect of dilutive securities:
Effect of dilutive securities, share-based compensation	324	268
Time-based Restricted Stock Units
Effect of dilutive securities:
Effect of dilutive securities, share-based compensation	1,132	957
Performance-based Restricted Stock Units
Effect of dilutive securities:
Effect of dilutive securities, share-based compensation	222	13
Restricted Stock
Effect of dilutive securities:
Effect of dilutive securities, share-based compensation	166	136
Employee Stock
Effect of dilutive securities:
Effect of dilutive securities, share-based compensation	7	6
0.75% Convertible Senior Notes due 2024
Numerator:
Add back interest expense, net of tax benefit, on assumed conversion of convertible notes	$ 444
Effect of dilutive securities:
Effect of dilutive securities, convertible notes	14,934
1.50% Convertible Senior Notes due 2026
Numerator:
Add back interest expense, net of tax benefit, on assumed conversion of convertible notes	$ 666
Effect of dilutive securities:
Effect of dilutive securities, convertible notes	14,934