Sale of Zohydro ER business - Narrative (Details) - USD ($)		3 Months Ended		9 Months Ended
	Apr. 24, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of business				$ 80,926,000	$ 89,624,000
Net product revenue		$ 0	$ 0	0	9,840,000
Stock-based compensation				5,821,000	7,334,000
Zohydro ER
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of business	$ 80,000,000
Restricted cash	$ 10,000,000
Potential indemnification period	12 months
Common stock received	$ 10,614,000
Supply commitment remaining amount	2,057,000
Potential additional cash payments	283,500,000
Regulatory milestone payment	12,500,000
Potential sales milestone	271,000,000
Purchase discounts	2,400,000
Net gain on sale of business	73,101,000
Zohydro ER | Ferrimill Limited
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net product revenue	926,000
Zohydro ER | Ferrimill Limited | Indemnification Agreement
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Maximum indemnification amount	$ 5,000,000
Zohydro ER | Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stock-based compensation				905,000	1,400,000
Amortization				$ 166,000	$ 333,000