Revenues, Recognition and Allowances - Disaggregation of Revenue (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]
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 sales
Disaggregation of Revenue [Line Items]
Revenue, net									59,591	50,955	45,002
Contract manufacturing sales
Disaggregation of Revenue [Line Items]
Revenue, net									6,047	8,995	17,033
Research and development services and other income
Disaggregation of Revenue [Line Items]
Revenue, net									227	252	977
Topical
Disaggregation of Revenue [Line Items]
Revenue, net									35,118	29,446	29,011
Injectables
Disaggregation of Revenue [Line Items]
Revenue, net									$ 24,473	$ 21,509	$ 15,991