Subsequent Event - Additional Information (Details) - USD ($)						9 Months Ended
	Nov. 07, 2018	Nov. 06, 2018	Sep. 02, 2018	Mar. 08, 2018	Sep. 01, 2016	Sep. 30, 2018	Sep. 30, 2017
Subsequent Event [Line Items]
Repayments under lines of credit						$ 68,581,000	$ 74,056,000
Amended credit facility with MidCap
Subsequent Event [Line Items]
Latest date of minimum liquidity covenant				2019-03
Amended credit facility with MidCap | Minimum
Subsequent Event [Line Items]
Effective date of financial covenants of amended credit facility				2018-04
Amended credit facility with MidCap | Maximum
Subsequent Event [Line Items]
Effective date of financial covenants of amended credit facility				2019-04
Subsequent Event | Amended credit facility with MidCap
Subsequent Event [Line Items]
Latest date of minimum liquidity covenant		2020-03
Subsequent Event | Amended credit facility with MidCap | Minimum
Subsequent Event [Line Items]
Effective date of financial covenants of amended credit facility		2019-04
Subsequent Event | Amended credit facility with MidCap | Maximum
Subsequent Event [Line Items]
Effective date of financial covenants of amended credit facility		2020-04
Squadron Credit Agreement
Subsequent Event [Line Items]
Current interest rate		10.30%
Squadron Credit Agreement | Subsequent Event
Subsequent Event [Line Items]
Debt instrument, aggregate principal to be paid on installments		$ 10,000,000
Debt instrument, frequency of periodic payment		29 equal monthly installments
Debt instrument payment at maturity		$ 25,000,000
Debt instrument, maturity date		Nov. 30, 2023
Squadron Credit Agreement | Subsequent Event | Common Stock
Subsequent Event [Line Items]
Number of warrants issued (in shares)		845,000
Exercise price of warrants (dollars per share)		$ 3.15
Warrants term		7 years
Term Loan | Squadron Credit Agreement | Subsequent Event
Subsequent Event [Line Items]
Secured debt agreement		$ 35,000,000
Proceeds from secured term loan		$ 33,800,000
Line of credit | Squadron Credit Agreement | Subsequent Event | LIBOR
Subsequent Event [Line Items]
Line of credit, expiration period		5 years
Interest rate description		LIBOR plus 8%
Basis spread		8.00%
Line of credit | Globus facility agreement
Subsequent Event [Line Items]
Line of credit						$ 29,200,000
Line of credit, expiration period					5 years
Line of credit | Globus facility agreement | LIBOR
Subsequent Event [Line Items]
Interest rate description			LIBOR plus 13.0%,			LIBOR plus 8.0%
Basis spread			13.00%			8.00%
Line of credit | Globus facility agreement | Subsequent Event
Subsequent Event [Line Items]
Repayments under lines of credit	$ 29,200,000