Sale of Zohydro ER business - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Apr. 24, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of business				$ 80,926	$ 89,624
Net product revenue		$ 0	$ 3,355	0	9,840
Stock-based compensation				4,465	5,292
Zohydro ER
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of business	$ 80,000
Restricted cash	$ 10,000
Potential indemnification period	12 months
Common stock received	$ 10,614
Supply commitment remaining amount	2,057
Potential additional cash payments	283,500
Regulatory milestone payment	12,500
Potential sales milestone	271,000
Purchase discounts	2,400
Net gain on sale of business	75,575
Zohydro ER | Ferrimill Limited
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net product revenue	900
Zohydro ER | Ferrimill Limited | Indemnification Agreement
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Maximum indemnification amount	$ 5,000
Zohydro ER | Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stock-based compensation				898	974
Amortization				$ 166	$ 209