Quarterly Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, $ 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
Quarterly Financial Data (unaudited) [Abstract]
Revenues	$ 16,824	$ 13,267	$ 13,928	$ 23,411	$ 12,194	$ 27,146	$ 11,142	$ 16,436	$ 67,430	$ 66,918
Manufacture and supply	4,787	5,592	4,973	5,636	5,615	4,880	5,141	4,184	20,988	19,820
Total costs and expenses	29,173	22,471	46,614	18,106	19,450	16,725	15,201	15,655	116,364	67,031
Net income (loss)	$ (13,944)	$ (15,038)	$ (36,493)	$ 4,099	$ (10,040)	$ 8,451	$ (5,897)	$ (1,457)	$ (61,376)	$ (8,943)
Basic and diluted net income (loss) per common share (in dollars per share)	$ (0.56)	$ (0.64)	$ (1.90)	$ 0.27					$ (2.96)