Debt - Summary of Interest Expense Components (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Debt Instrument [Line Items]
Amortization of debt issuance costs	$ 62	$ 103	$ 281	$ 226
Amortization of debt discount associated with SWK Warrants 1 and 2 (defined below)	71	479	608	1,286
Mark to market of SWK Warrant 2 (defined below)	0	0	0	59
Total	746	878	2,207	2,678
2013 Loan and Security Agreement
Debt Instrument [Line Items]
Write-off of debt issuance costs related to 2013 Loan and Security Agreement	0	0	0	282
Term Loans | A&R Credit Agreement
Debt Instrument [Line Items]
Interest expense	266	171	583	512
Accretion of termination fees (over term of Term Loan at rate of 8%)	115	$ 53	$ 255	$ 144
Amortization of debt issuance costs	$ 75
Effective interest rate (as percent)	13.81%	12.50%	13.81%	12.50%
Accretion of termination fees over Term Loan (as percent)	8.00%	8.00%	8.00%	8.00%
Line of Credit | 2013 Loan and Security Agreement
Debt Instrument [Line Items]
Interest expense	$ 0	$ 0	$ 0	$ 49
Line of Credit | 2016 Credit and Security Agreement
Debt Instrument [Line Items]
Interest expense	111	72	309	120
Line of Credit | Seasonal Facility
Debt Instrument [Line Items]
Interest expense	69	0	92	0
Subordinated Debt | Subordinated Promissory Note
Debt Instrument [Line Items]
Interest expense	44	0	67	0
Capital Leases
Debt Instrument [Line Items]
Interest expense	6	0	8	0
Other
Debt Instrument [Line Items]
Interest expense	$ 2	$ 0	$ 4	$ 0