Divestiture and Sale of Zohydro ER business - Results of Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net loss (income) from discontinued operations	$ 75	$ (134)	$ (555)	$ (181)	$ 109	$ (379)	$ (582)	$ (169)	$ (795)	$ (1,021)	$ 67,848
Zohydro ER [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net product revenue									57	532	11,299
Cost of product sold									0	15	2,205
Royalty expense									3	32	835
Research and development									0	0	5,504
Selling, general and administrative									920	1,594	14,820
Restructuring expense									0	0	588
Gain on sale of business									0	0	(89,484)
Total operating expense (income)									923	1,641	(65,532)
Other income									0	0	5,077
Net (loss) income from discontinued operations before tax									(866)	(1,109)	81,908
Tax benefit (expense)									71	88	(14,060)
Net loss (income) from discontinued operations									$ (795)	$ (1,021)	$ 67,848