Segment Information Revenues By Region (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Revenues from External Customers [Line Items]
Revenues		$ 614,576	$ 607,221
United States and Canada [Member]
Revenues from External Customers [Line Items]
Revenues		397,566	355,932
Europe, Middle East, and Africa [Member]
Revenues from External Customers [Line Items]
Revenues		171,242	202,074
Other [Member]
Revenues from External Customers [Line Items]
Revenues	[1]	$ 45,768	$ 49,215

[1] Other includes our operations in Latin America and Asia Pacific.