Income Taxes - Components of Net Income Before Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Components of net income before income taxes
Domestic									$ 77,721	$ 93,510	$ 80,234
India									6,245	4,769	2,173
Foreign Other									1,390	7,444	4,580
Income before income taxes	$ 19,688	$ 22,742	$ 14,250	$ 28,676	$ 24,214	$ 28,821	$ 26,837	$ 25,851	$ 85,356	$ 105,723	$ 86,987