Notes Payable - Additional Information (Detail) - Loan and Security Agreement [Member] - USD ($) | Apr. 01, 2020 | Mar. 31, 2017 | Oct. 31, 2016 | Mar. 31, 2020 | Dec. 31, 2019 | Jul. 01, 2020 |
Subsequent Event [Member] | | | | | | |
Debt Instrument [Line Items] | | | | | | |
Minimum cash balance required in deposit account | $ 1,000,000 | | | | | |
Tranche One [Member] | Subsequent Event [Member] | | | | | | |
Debt Instrument [Line Items] | | | | | | |
Debt instrument, maturity date | Aug. 1, 2020 | | | | | |
Tranche Two [Member] | Subsequent Event [Member] | | | | | | |
Debt Instrument [Line Items] | | | | | | |
Debt instrument, maturity date | Jan. 1, 2021 | | | | | |
LIBOR [Member] | | | | | | |
Debt Instrument [Line Items] | | | | | | |
Debt instrument, interest rate floor | | | 0.50% | | | |
Horizon Technology Finance Corporation and Silicon Valley Bank [Member] | | | | | | |
Debt Instrument [Line Items] | | | | | | |
Loan borrowed amount | | | $ 20,000,000 | | | |
Debt instrument, interest rate floor | | | 10.50% | | | |
Variable rate basis | | | | one-month LIBOR | | |
Interest rate description | | | | Each loan tranche bears interest at a floating rate equal to 10.5% plus the amount by which the one-month London Interbank Offer Rate (“LIBOR”) exceeds 0.5%. | | |
Prepayment penalty fee | | | 2.00% | | | |
Minimum cash balance required in deposit account | | | | $ 2,500,000 | | |
Debt instrument covenant description | | | | Beginning July 1, 2020, until the repayment of the full amounts due under the Loan Agreement, the Company must maintain a minimum cash balance equal to the lesser of (i) $1.0 million or (ii) the then-current aggregate outstanding principal balance of the loans. | | |
Additional default interest rate | | | | 5.00% | | |
Allocated fair value of warrants issued | | | | $ 900,000 | $ 900,000 | |
Horizon Technology Finance Corporation and Silicon Valley Bank [Member] | Subsequent Event [Member] | | | | | | |
Debt Instrument [Line Items] | | | | | | |
Minimum cash balance required in deposit account | | | | | | $ 1,000,000 |
Horizon Technology Finance Corporation and Silicon Valley Bank [Member] | Tranche One [Member] | | | | | | |
Debt Instrument [Line Items] | | | | | | |
Loan borrowed amount | | | $ 12,500,000 | | | |
Debt instrument, payment terms | | | | The Company borrowed the first tranche of $12.5 million upon close of the Loan Agreement in October 2016. The first tranche originally required only monthly interest payments until May 1, 2018 followed by equal monthly payments of principal plus accrued interest through the scheduled maturity date on May 1, 2020. | | |
Debt instrument, final payment | | | $ 800,000 | | | |
Debt instrument, maturity date | | | May 1, 2020 | | | |
Debt instrument, frequency of periodic Payment | | | | monthly | | |
Horizon Technology Finance Corporation and Silicon Valley Bank [Member] | Tranche Two [Member] | | | | | | |
Debt Instrument [Line Items] | | | | | | |
Loan borrowed amount | | $ 7,500,000 | | | | |
Debt instrument, payment terms | | | | The Company borrowed the second tranche of $7.5 million in March 2017. The second tranche required only monthly interest payments until October 1, 2018 followed by equal monthly payments of principal plus accrued interest through the scheduled maturity date on October 1, 2020. | | |
Debt instrument, final payment | | | $ 500,000 | | | |
Debt instrument, maturity date | | | Oct. 1, 2020 | | | |
Debt instrument, frequency of periodic Payment | | | | monthly | | |
Horizon Technology Finance Corporation and Silicon Valley Bank [Member] | Tranche One And Two [Member] | | | | | | |
Debt Instrument [Line Items] | | | | | | |
Debt instrument, payment terms | | | | the total amount of the payment was increased to $0.6 million. For each of the first and second tranches, the April Amendment requires only monthly interest payments on the outstanding principal balance for the amounts due on April 1, 2020, May 1, 2020 and June 1, 2020. Beginning with the amounts due on July 1, 2020, the Company will resume payment of the principal portion of these loans in accordance with the original amounts due | | |
Debt instrument, final payment | | | | $ 600,000 | | |