Basis of Presentation and Significant Accounting Policies - Summary of Changes in Level 3 Fair Value Measurements (Details) - Level 3 - USD ($) $ in Thousands		3 Months Ended
	Dec. 14, 2015	Dec. 31, 2018
PFG V Debt, Net of Discount
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of September 30, 2018		$ 1,905
Disbursement of Tranche 2, net of discount	$ 2,300	471
Payments to PFG		(83)
Amortization and accretion expense		24
Balance as of December 31, 2018		2,317
Warrant Debt, PFG V
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of September 30, 2018		103
Disbursement of Tranche 2, net of discount		26
Payments to PFG		0
Amortization and accretion expense		4
Balance as of December 31, 2018		$ 133