Long Term Debt - Hercules Loan Agreement - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended
	Jun. 30, 2019	Oct. 31, 2018	Mar. 31, 2020	Mar. 31, 2019
Schedule Of Long Term Debt [Line Items]
Loss on extinguishment of debt			$ (162,000)	$ 0
Hercules Loan Agreement
Schedule Of Long Term Debt [Line Items]
Proceeds from lines of credit		$ 10,000,000.0
Amended and Restated Loan Agreement
Schedule Of Long Term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 35,000,000.0
Long-term line of credit	20,000,000.0		20,000,000.0
Line of credit facility, outstanding	$ 10,000,000.0
Debt instrument variable percentage	8.75%
Interest rate increase percentage	4.00%
Amended and Restated Loan Agreement | Prime Rate
Schedule Of Long Term Debt [Line Items]
Debt instrument variable percentage	2.75%
Amended and Restated Loan Agreement | New Borrowings
Schedule Of Long Term Debt [Line Items]
Line of credit facility, current borrowing capacity	$ 10,000,000.0
The Amended Loan Agreement
Schedule Of Long Term Debt [Line Items]
Line of credit facility, maximum borrowing capacity			$ 50,000,000.0
Debt instrument variable percentage			8.75%
Interest rate increase percentage			4.00%
Contingent additional term loan advances, tranche one			$ 7,500,000
Contingent additional term loan advances, tranche two			7,500,000
Contingent additional term loan advances, tranche three			10,000,000.0
Line of credit facility periodic payment			$ 800,000
Line of credit principal amount drawn percentage			4.00%
Threshold outstanding principal amount of advances			$ 25,000,000.0
Cash on hand requirement			$ 30,000,000.0
Cash on hand requirement, multiplier			6
Cash on hand requirement, reduction level			$ 20,000,000.0
Cash on hand requirement, multiplier, reduction level			3
Maximum rights to purchase equity securities			$ 3,000,000.0
Rights to purchase equity securities, amount exercised			1,000,000.0
Loss on extinguishment of debt			162,000
Interest expense, debt			$ 584,000	$ 357,000
Effective interest rate of loan			10.70%
Principal payments			$ 0
The Amended Loan Agreement | Interest Expense
Schedule Of Long Term Debt [Line Items]
Amortization of debt discount			118,000
Accretion in period			$ 113,000
The Amended Loan Agreement | Prime Rate
Schedule Of Long Term Debt [Line Items]
Debt instrument variable percentage			3.75%
The Amended Loan Agreement | Maximum | Period One
Schedule Of Long Term Debt [Line Items]
Debt instrument prepayment premium, percentage			2.00%
The Amended Loan Agreement | Maximum | Period Two
Schedule Of Long Term Debt [Line Items]
Debt instrument prepayment premium, percentage			1.00%
The Amended Loan Agreement | Maximum | Period Three
Schedule Of Long Term Debt [Line Items]
Debt instrument prepayment premium, percentage			0.50%
The Amended Loan Agreement | Term Loan
Schedule Of Long Term Debt [Line Items]
Line of credit facility, maximum borrowing capacity			$ 25,000,000.0
Additional borrowing capacity	$ 5,000,000.0