Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 190,045	$ 92,287
Work in process	302,042	202,301
Finished goods	21,791	13,334
Deferred costs	212,260	91,434
Total Inventories	$ 726,138	$ 399,356