Operating Segments and Related Information (Details 5) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Business Unit Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 439,618	$ 406,814
United States
Business Unit Reporting, Revenue Reconciling Item [Line Items]
Revenue	225,444	221,832
Europe [Member]
Business Unit Reporting, Revenue Reconciling Item [Line Items]
Revenue	97,523	83,271
Asia [Member]
Business Unit Reporting, Revenue Reconciling Item [Line Items]
Revenue	61,373	53,924
Mid_East/Africa [Member]
Business Unit Reporting, Revenue Reconciling Item [Line Items]
Revenue	36,407	25,142
Canada/Latin America
Business Unit Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 18,871	$ 22,645