Notes Payable - Maturities of Long-Term Debt (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
Maturities of Long-term Debt
Remainder 2016	$ 1,667		$ 1,667
2017	3,333		3,333
2018	2,500		2,500
Total	7,500		7,500
Less: discount for warrants and costs paid to lender	(184)		(184)
Less: current portion	(3,207)		(3,207)
Note payable, net of current portion and discount	4,109		4,109		$ 5,720
Credit Facility
Maturities of Long-term Debt
Interest expense	$ 200	$ 300	$ 500	$ 400