Term Notes - Schedule of Long-term Debt and Net Discount or Premium Balance (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument Periodic Payment [Abstract]
Principal amount of term note	$ 16,500	$ 13,334
Net (discount) premium associated with accretion of final payment, issuance of common stock warrants, and other debt issuance costs	(49)	485
Term note, current and noncurrent	16,451	13,819
Less term note, current portion	(1,650)	(6,667)
Term note, noncurrent portion	$ 14,801	$ 7,152

Face (par) amount of debt instrument at time of issuance.

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Amount, after accumulated amortization, of debt discount (premium).

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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