Sale of Zohydro ER business - Narrative (Details) - USD ($)		1 Months Ended	12 Months Ended
	Apr. 24, 2015	May 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of businesses			$ 0	$ 82,984,000	$ 89,624,000
Net product revenue			0	0	9,840,000
Stock-based compensation			7,353,000	7,686,000	9,492,000
Zohydro ER [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of businesses	$ 80,000,000
Escrow deposit	10,000,000
Indemnification period		12 months
Consideration received, common stock	10,614,000
Potential cash receipts based on achievement of milestones	283,500,000
Net gain on sale of business	$ 75,424,000
Other income			$ 0	5,077,000	8,500,000
Zohydro ER [Member] | Regulatory Exclusivity Rights [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other income				5,000,000	5,000,000
Zohydro ER [Member] | Carncinogenicity Data [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other income					3,500,000
Discontinued Operations [Member] | Zohydro ER [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stock-based compensation				745,000	1,956,000
Amortization				$ 166,000	$ 558,000