Leases and Rentals - Schedule of Capital Leases Included in Plant, Property and Equipment, Net (Details) - Machinery and equipment - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]    
Machinery and equipment $ 1,625 $ 1,625
Accumulated depreciation (1,504) (1,409)
Machinery and equipment, net $ 121 $ 216