Other Assets and Liabilities - Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Other Non-Current Liabilities:
Provision for retirement indemnity	$ 1,003	$ 1,024
Customer allowances	619	1,352
Unrecognized tax benefits	5,315	5,315
Guarantee to Deerfield	5,574	5,717
Other	66	594
Total	$ 12,577	$ 14,002