Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Accrued Expenses
Accrued compensation	$ 7,711	$ 5,784	$ 5,011
Accrued professional fees	7,309	2,049	2,051
Accrued clinical trial and clinical supply costs	1,693	2,942	877
Accrued sales and marketing expenses	1,007	1,017	807
Accrued product costs	966	3,014	1,909
Accrued interest expense	492	639	1,292
Other accrued expenses	2,476	2,211	1,165
Total	$ 21,654	$ 17,656	$ 13,112