Sale of Zohydro ER business - Results of Discontinued Operations (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
	Apr. 24, 2015	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring expense										$ 588
Net income (loss) from discontinued operations		$ 3,019	$ (1,635)	$ 79,160	$ (12,696)	$ (11)	$ (11)	$ (15)	$ (16)	67,848	$ (52,900)	$ (8,255)
Zohydro ER [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net product revenue										11,299	11,584	0
Cost of product sold										2,205	10,554	0
Royalty expense										835	1,127	0
Research and development										5,504	7,043	4,433
Selling, general and administrative										14,820	54,260	3,822
Restructuring expense										588	0	0
Gain on sale of business	$ (89,484)									(89,484)	0	0
Total operating (income) expense										(65,532)	72,984	8,255
Other income										5,077	8,500	0
Net income (loss) from discontinued operations before tax										81,908	(52,900)	(8,255)
Income tax expense		$ 3,472	$ 5,496	$ 6,946						(14,060)	0	0
Net income (loss) from discontinued operations										$ 67,848	$ (52,900)	$ (8,255)