Material Agreements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended	182 Months Ended	189 Months Ended
	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2019	Feb. 20, 2019	Sep. 30, 2019
Commercial Exploitation Agreement with Indivior [Member]
Agreements [Abstract]
License agreement term			7 years
Automatic renewal period of agreement			1 year
Commercial Exploitation Agreement with Indivior [Member] | Minimum [Member]
Agreements [Abstract]
Notice period of intent not to renew agreement			1 year
Supplemental Agreement with Indivior [Member]
Agreements [Abstract]
Contingent payments receivable in the future	$ 34,250		$ 34,250		$ 34,250
Revenues		$ 4,250		$ 40,750
Supplemental Agreement with Indivior [Member] | Maximum [Member]
Agreements [Abstract]
Contingent payments receivable in the future	75,000		75,000		75,000
Supplemental Agreement with Indivior Performance or Event-Based Milestones [Member]
Agreements [Abstract]
Contingent payments receivable in the future	33,000		33,000		33,000
Supplemental Agreement with Indivior Additional Process Patent Rights to the Company [Member]
Agreements [Abstract]
Contingent payments receivable in the future	1,250		1,250		1,250
License Agreement with Sunovion Pharmaceuticals, Inc. [Member]
Agreements [Abstract]
Revenues	0		0		18,000
License Agreement with Sunovion Pharmaceuticals, Inc Milestones [Member]
Agreements [Abstract]
Revenues					13,000
License Agreement with Sunovion Pharmaceuticals, Inc Milestones [Member] | Maximum [Member]
Agreements [Abstract]
Contingent payments receivable in the future	$ 45,000		$ 45,000		45,000
License Agreement with Sunovion Pharmaceuticals, Inc. Upfront [Member]
Agreements [Abstract]
Revenues					$ 5,000
Agreement to Terminate CLA with KemPharm [Member]
Agreements [Abstract]
Percentage share of milestone payments paid	10.00%
Agreement to Terminate CLA with KemPharm [Member] | License and Royalty Revenue [Member]
Agreements [Abstract]
Revenues	$ 1,000