Sale of Zohydro ER business - Gain on Sale of Business (Details) - Zohydro ER - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Apr. 24, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Non-contingent consideration received	$ 93,597
Carrying value of assets transferred to Ferrimill	(2,516)	$ 6,027		$ 6,027		$ 9,869
Transaction costs	(2,028)
Net gain on sale of business before income tax	89,053	$ 89,053	$ 0	$ 89,053	$ 0
Income tax expense	(13,478)
Net gain on sale of business	$ 75,575