Certain Balance Sheet Components Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Inventory [Line Items]
Inventory, Raw Materials, Net of Reserves	$ 126,656	$ 103,274
Inventory, Work in Process, Net of Reserves	9,863	7,925
Inventory, Finished Goods, Net of Reserves	57,316	51,850
Total inventories	$ 193,835	$ 163,049