Other Assets and Liabilities - Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accrued Expenses
Accrued compensation	$ 2,533	$ 3,157
Accrued social charges	595	1,204
Accrued employee severance (see Note 13)	824	1,000
Customer allowances	11,747	10,613
Accrued ELAA payment (1)	20,000	20,000
Accrued contract manufacturing organization charges	2,095	2,327
Accrued contract sales organization and marketing costs	3,514	7,641
Other	4,640	4,984
Total	$ 45,948	$ 50,926