Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) [Abstract]
Revenues	$ 12,418	$ 13,267	$ 36,190	$ 50,606
Costs and expenses:
Manufacture and supply	4,643	5,592	13,569	16,201
Research and development	5,063	4,534	17,517	17,429
Selling, general and administrative	13,714	12,346	47,868	53,559
Total costs and expenses	23,420	22,472	78,954	87,189
Loss from operations	(11,002)	(9,205)	(42,764)	(36,583)
Other income/(expenses):
Interest expense	(2,652)	(1,933)	(6,515)	(5,809)
Interest income	138	216	565	238
Loss on the extinguishment of debt	(4,896)	0	(4,896)	0
Change in fair value of warrant	0	(4,116)	0	(5,278)
Net loss before income taxes	(18,412)	(15,038)	(53,610)	(47,432)
Income taxes	0	0	0	0
Net loss	(18,412)	(15,038)	(53,610)	(47,432)
Comprehensive loss	$ (18,412)	$ (15,038)	$ (53,610)	$ (47,432)
Net loss per share - basic and diluted (in dollars per share)	$ (0.74)	$ (0.64)	$ (2.15)	$ (2.45)
Weighted-average number of common shares outstanding - basic and diluted (in shares)	25,031,478	23,646,192	24,992,229	19,335,541