Discontinued operations - Income Statement and Balance Sheet Disclosures Related to Zohydro (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax benefit (expense)		$ 2,520		$ 15,998
Net income (loss) from discontinued operations	$ (379)	(1,635)	$ (1,130)	64,829
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Total current assets of discontinued operations	6		6		$ 208
Total current liabilities of discontinued operations	1,203		1,203		2,906
Zohydro ER
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net product revenue	(53)	1,280	238	10,459
Cost of product sold	0	182	15	2,134
Royalty expense	0	77	17	785
Research and development	0	(232)	0	5,596
Selling, general and administrative	414	472	1,424	14,706
Restructuring expense	0	20	0	588
(Gain) on sale of business	0	46	0	89,099
Total operating (income) expense	414	473	1,456	(65,290)
Other income	0	78	0	5,078
Net income (loss) from discontinued operations before tax	(467)	885	(1,218)	80,827
Income tax benefit (expense)	(88)	2,520	(88)	15,998
Net income (loss) from discontinued operations	(379)	$ (1,635)	(1,130)	$ 64,829
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Prepaid expenses and other current assets	6		6		208
Total current assets of discontinued operations	6		6		208
Total assets of discontinued operations	6		6		208
Accounts payable	334		334		0
Accrued expenses	869		869		2,796
Deferred revenue and other current liabilities	0		0		110
Total current liabilities of discontinued operations	1,203		1,203		2,906
Total liabilities of discontinued operations	$ 1,203		$ 1,203		$ 2,906