Segment Information - Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Revenues	$ 689,246	$ 708,372
North America
Segment Reporting Information [Line Items]
Revenues	414,948	415,877
International | EMEA
Segment Reporting Information [Line Items]
Revenues	216,349	229,544
International | Latin America
Segment Reporting Information [Line Items]
Revenues	75,250	74,468
International | Asia Pacific
Segment Reporting Information [Line Items]
Revenues	73,579	80,122
Operating Segments
Segment Reporting Information [Line Items]
Revenues	780,126	800,011
Operating Segments | International
Segment Reporting Information [Line Items]
Revenues	365,178	384,134
Segment Reconciling Items
Segment Reporting Information [Line Items]
Revenues	$ (90,880)	$ (91,639)