Inventory (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Inventory
Work-in-process	$ 17,277	$ 17,555
Finished goods	1,309	1,783
Total inventories	18,586	19,338
Inventories - current	1,309	1,783	[1]
Inventories - non -current	$ 17,277	$ 17,555	[1]
Shelf life for finished goods inventory, maximum	36 months

[1] The condensed consolidated balance sheet at December 31, 2015 has been derived from the audited financial statements at that date.