Revenues, Recognition and Allowances - Adjustments to Gross Product Sales (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Gross product sales									$ 158,278	$ 215,883	$ 217,633
Reduction to gross product sales:
Chargebacks and billbacks									60,770	125,159	141,343
Wholesaler fees for service									5,503	7,049	3,869
Sales discounts and other allowances									32,414	32,720	27,419
Total reduction to gross product sales									98,687	164,928	172,631
Revenue, net	$ 16,777	$ 18,294	$ 16,249	$ 14,545	$ 14,767	$ 11,340	$ 16,432	$ 17,663	65,865	60,202	63,012
Company Product
Reduction to gross product sales:
Revenue, net									59,591	50,955	45,002
Contract Manufacturing Product
Reduction to gross product sales:
Revenue, net									6,047	8,995	17,033
Product sales, net
Reduction to gross product sales:
Revenue, net									$ 65,865	$ 60,202	$ 63,012