Other Assets and Liabilities - Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Accrued Expenses
Accrued compensation	$ 3,115	$ 3,157
Accrued social charges	923	1,204
Accrued employee severance (see Note 13)	633	1,000
Customer allowances	7,813	10,613
Accrued Exclusive License and Assignment Agreement (ELAA) payment	0	20,000
Accrued contract manufacturing organization charges	1,076	2,327
Accrued contract sales organization and marketing costs	3,999	7,641
Other	3,934	4,984
Total	$ 21,493	$ 50,926