Income Taxes - Schedule of Income Before Provision for Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes
Domestic									$ 78,812	$ 51,194	$ 51,552
Foreign									11,943	11,305	11,253
Income before provision for income taxes	$ 46,627	$ 10,628	$ 20,399	$ 13,101	$ 11,494	$ 18,938	$ 18,413	$ 13,654	$ 90,755	$ 62,499	$ 62,805