Ferring Asset Purchase Agreement and Discontinued Operations - Operating Results of Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Asset Purchase Agreement and Discontinued Operations [Line Items]
Gain on sale					$ 12,317
Income from discontinued operations	$ (24)	$ 248	$ (24)	$ 11,740
Product Business outside the U.S. | Discontinued Operations
Asset Purchase Agreement and Discontinued Operations [Line Items]
Product sales	0	0	0	143
Royalty revenue	0	147	0	368
Cost of goods sold	(24)	0	(24)	(74)
Operating expenses	0	(149)	0	(748)
Other expense	0	0	0	(16)
Gain on sale	0	250	0	12,067
Income from discontinued operations	$ (24)	$ 248	$ (24)	$ 11,740