Stock-Based Compensation - Costs Related to Company's Stock-Based Compensation Plan (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expenses	$ 10,894	$ 8,346	$ 28,796	$ 20,850
Cost of revenues
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expenses	2,198	1,723	5,588	4,765
General and administrative expenses
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expenses	4,431	3,358	12,337	8,038
Selling and marketing expenses
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expenses	$ 4,265	$ 3,265	$ 10,871	$ 8,047