Fair Value Measurements - Additional Information (Detail) - USD ($)				1 Months Ended			6 Months Ended
	Mar. 28, 2019	Jun. 26, 2018	Mar. 28, 2018	Apr. 30, 2019	Sep. 30, 2018	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exercise price of issued warrants							$ 0	$ 1.23
Remeasurement of second tranche transaction liability to fair value description							This valuation at settlement was calculated as the excess of the sum of (i) the fair value of the Second Tranche Warrants and (ii) the fair value of the shares of Common Stock issued to settle the liability over the cash proceeds received by the Company for the Units.
Proceeds from issuance of stock, net of issuance costs					$ 28,900,000		$ 18,343,000	$ 34,471,000
Transaction costs allocated to second tranche liability and additional advance warrant liability							$ 326,000
Senior Secured Term Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proceeds from issuance of stock, net of issuance costs				$ 18,300,000
Senior Secured Term Loan [Member] | Warrant [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exercise price of issued warrants		$ 1.93	$ 1.10
Additional Advance [Member] | Senior Secured Term Loan [Member] | Warrant [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exercise price of issued warrants		$ 1.93
Warrants, contingent issuance fair value			$ 69,000
Revaluation of additional advance warrants shares reclassified to equity		$ 87,000				$ 87,000
Initial Advance [Member] | Senior Secured Term Loan [Member] | Warrant [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exercise price of issued warrants			$ 1.10
Fair value of warrants issued			$ 284,000
Second Tranche Transaction [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Common Stock purchase price description							The purchase price for each share of Common Stock issuable in the Second Tranche Transaction was defined as the lower of (a) $1.265 (which was a 15% premium to the First Tranche Purchase Price) and (b) a 20% discount to the volume weighted average price (“VWAP”) of the shares of Common Stock on the Nasdaq Stock Market for the 20 trading days immediately prior to the closing of the Second Tranche Transaction; provided, however, that the purchase price could not be lower than $0.88, which was a 20% discount to the First Tranche Purchase Price.
Percentage discount to volume weighted average price for 20 days immediately preceding the closing of the Second Tranche Transaction	20.00%
Second Tranche Transaction [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Common stock price per share	$ 1.265
Percentage of premium to first tranche share purchase price	15.00%
Second Tranche Transaction [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Common stock price per share	$ 0.88
Percentage of discount to first tranche share purchase price	20.00%
Second Tranche Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage discount to volume weighted average price for 20 days immediately preceding the closing of the Second Tranche Transaction					20.00%
Warrant purchase price description							The exercise price of each Second Tranche Warrant was an amount equal to the lower of (a) $1.43 (a 30% premium to the First Tranche Purchase Price) and (b) a 20% discount to the VWAP of the shares of the Company’s Common Stock on Nasdaq for the 20 trading days immediately prior to the exercise of a Second Tranche Warrant; provided, however, that the exercise price could not be lower than $0.88, which was a 20% discount to the First Tranche Purchase Price.
Exercise price of issued warrants					$ 1.43
Second Tranche Warrants [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exercise price of issued warrants					$ 1.43
Percentage of premium to first tranche share purchase price					30.00%
Second Tranche Warrants [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of discount to first tranche share purchase price					20.00%
Exercise price of issued warrants					$ 0.88