Revenue Disaggregated Revenue by Geography (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 360,460,000	$ 331,514,000	$ 732,493,000	$ 579,253,000
EMEA [Member]
Disaggregation of Revenue [Line Items]
Revenues	33,867,000	31,905,000	73,391,000	56,858,000
Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Revenues	18,410,000	15,673,000	37,034,000	27,089,000
Latin America [Member]
Disaggregation of Revenue [Line Items]
Revenues	15,557,000	19,208,000	28,650,000	25,685,000
North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	17,810,000	16,537,000	36,945,000	28,098,000
Other foreign countries [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0	80,000	0
Foreign [Member]
Disaggregation of Revenue [Line Items]
Revenues	85,644,000	83,323,000	176,100,000	137,730,000
UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues	$ 274,816,000	$ 248,191,000	$ 556,393,000	$ 441,523,000