Discontinued operations - Income Statement and Balance Sheet Disclosures Related to Zohydro (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax expense		$ 13,478
Net income (loss) from discontinued operations	$ (582)	79,160	$ (751)	$ 66,464
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Total current assets of discontinued operations	0		0		$ 208
Total current liabilities of discontinued operations	1,537		1,537		2,906
Zohydro ER
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net product revenue	(43)	4,173	291	9,179
Cost of product sold	0	612	15	1,952
Royalty expense	0	291	17	708
Research and development	0	1,020	0	5,829
Selling, general and administrative	539	3,097	1,010	14,233
Restructuring expense	0	568	0	568
Gain on sale of business	0	89,053	0	89,053
Total operating (income) expense	539	(83,465)	1,042	(65,763)
Other income	0	5,000	0	5,000
Net income (loss) from discontinued operations before tax	(582)	92,638	(751)	79,942
Income tax expense	0	13,478	0	13,478
Net income (loss) from discontinued operations	(582)	$ 79,160	(751)	$ 66,464
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Prepaid expenses and other current assets	0		0		208
Total current assets of discontinued operations	0		0		208
Total assets of discontinued operations	0		0		208
Accounts payable	182		182		0
Accrued expenses	1,355		1,355		2,796
Deferred revenue and other current liabilities	0		0		110
Total current liabilities of discontinued operations	1,537		1,537		2,906
Total liabilities of discontinued operations	$ 1,537		$ 1,537		$ 2,906