Operating Segments and Related Information (Details 5) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 434,124	$ 402,729	$ 840,938	$ 782,201
United States
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	224,025	224,305	445,856	418,589
Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	91,041	84,297	174,313	168,707
Asia [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	59,721	47,413	113,645	91,237
Mid_East/Africa [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	35,248	28,629	60,390	56,341
Canada/Latin_America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 24,089	$ 18,085	$ 46,734	$ 47,327