Property, Plant, and Equipment By Location (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Property, Plant, and Equipment by Location
Property, plant, and equipment, net	$ 200,768	$ 176,458
UNITED STATES [Member]
Schedule of Property, Plant, and Equipment by Location
Property, plant, and equipment, net	67,764	70,435
Outside United States [Member]
Schedule of Property, Plant, and Equipment by Location
Property, plant, and equipment, net	$ 133,004	$ 106,023