Segment Information and Enterprise Reporting Long-lived assets by geographic area (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$ 272,397	$ 225,167
Concentration Risk, Long-lived Asset Geographic Area, Percentage	100.00%	100.00%
Reportable Geographical Components | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$ 262,249	$ 216,784
Concentration Risk, Long-lived Asset Geographic Area, Percentage	96.30%	96.30%
Reportable Geographical Components | International
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$ 10,148	$ 8,383
Concentration Risk, Long-lived Asset Geographic Area, Percentage	3.70%	3.70%