Segment and Geographic Information - Summary (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) Segment	Jun. 30, 2018 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | Segment			1
Segment Reporting Information [Line Items]
Revenues	$ 346,874	$ 349,747	$ 693,951	$ 676,535
United States
Segment Reporting Information [Line Items]
Revenues	199,388	179,843	388,760	351,787
International
Segment Reporting Information [Line Items]
Revenues	147,486	169,904	305,191	324,748
Europe
Segment Reporting Information [Line Items]
Revenues	130,919	144,462	266,195	275,076
Other geographies
Segment Reporting Information [Line Items]
Revenues	$ 16,567	$ 25,442	$ 38,996	$ 49,672