Stockholders’ Equity and Stock-Based Compensation - Option Activities (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Number of Shares Underlying Outstanding Options
Outstanding, beginning balance (in shares)	3,430
Options granted (in shares)	0
Options exercised (in shares)	(538)
Options canceled (in shares)	(18)
Outstanding, ending balance (in shares)	2,874	3,430
Vested and exercisable (in shares)	2,059
Weighted- Average Exercise Price per Share
Outstanding, beginning balance (in dollars per share)	$ 45.17
Options granted (in dollars per share)	0
Options exercised (in dollars per share)	30.81
Options canceled (in dollars per share)	38.62
Outstanding, ending balance (in dollars per share)	47.90	$ 45.17
Vested and exercisable (in dollars per share)	$ 36.79
Weighted- Average Remaining Contractual Term (Years) and Aggregate Intrinsic Value of Stock Options
Weighted-average remaining contractual term of stock options outstanding	3 years 2 months 12 days	3 years 7 months 6 days
Weighted-average remaining contractual term of stock options vested and exercisable	2 years 9 months 18 days
Aggregate intrinsic value of stock options outstanding	$ 903,398	$ 841,659
Aggregate intrinsic value of stock options outstanding, vested and exercisable	$ 670,147