Segment Information Revenues By Region (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues from External Customers [Line Items]
Revenues		$ 624,474	$ 595,962	$ 1,874,087	$ 1,789,073
United States and Canada [Member]
Revenues from External Customers [Line Items]
Revenues		405,973	376,676	1,221,448	1,080,709
Europe, Middle East, and Africa [Member]
Revenues from External Customers [Line Items]
Revenues		157,159	177,356	495,715	564,178
Other [Member]
Revenues from External Customers [Line Items]
Revenues	[1]	$ 61,342	$ 41,930	$ 156,924	$ 144,186

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