Other Assets and Liabilities - Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Liabilities Disclosure [Abstract]
Provision for retirement indemnity	$ 1,024	$ 1,303	$ 2,431
Customer allowances	1,352	1,636
Unrecognized tax benefits	5,315	3,954	$ 1,686	$ 448
Guarantee to Deerfield	5,717	0
Other	594	191
Total	$ 14,002	$ 7,084