Debt - MidCap Facility Agreement (Details) - USD ($)		3 Months Ended	9 Months Ended	12 Months Ended
	Aug. 08, 2016	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Sep. 01, 2016	Mar. 11, 2016
Fifth amendment credit facility with MidCap | Revolving credit facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity						$ 22,500,000
Fifth amendment credit facility with MidCap | Term loan
Line of Credit Facility [Line Items]
Maximum borrowing capacity						5,000,000
Debt instrument, prepayment fee						$ 600,000
Amended credit facility with MidCap | Revolving credit facility
Line of Credit Facility [Line Items]
Line of credit			$ 12,200,000
Interest rate			6.50%
Amended credit facility with MidCap | Term loan
Line of Credit Facility [Line Items]
Line of credit			$ 4,900,000
Floor on interest rate			9.50%
Interest rate			9.50%
Third amendment credit facility with MidCap
Line of Credit Facility [Line Items]
Amendment fee amount							$ 500,000
Debt issuance costs			$ 2,100,000
Fourth Amendment to the amended credit facility with MidCap
Line of Credit Facility [Line Items]
Amendment fee amount	$ 200,000
Line of credit facility, increase in maximum borrowing capacity	$ 2,200,000.0
LIBOR | Amended credit facility with MidCap | Revolving credit facility
Line of Credit Facility [Line Items]
Interest rate description			LIBOR plus 6.0%
Basis spread			6.00%
LIBOR | Amended credit facility with MidCap | Term loan
Line of Credit Facility [Line Items]
Interest rate description			("LIBOR") plus 8.0%
Basis spread			8.00%
Forecast | Amended credit facility with MidCap
Line of Credit Facility [Line Items]
Monthly term loan payments		$ 100,000		$ 300,000	$ 200,000
Line of credit | Amended credit facility with MidCap | Maximum
Line of Credit Facility [Line Items]
Debt default, interest rate increase			5.00%