Debt - Additional Information (Detail)						1 Months Ended	9 Months Ended	12 Months Ended
	Oct. 28, 2019 USD ($)	May 07, 2019 USD ($) Day $ / shares shares	Nov. 09, 2018 USD ($) Day $ / shares shares	Sep. 27, 2018 USD ($) $ / shares shares	Mar. 06, 2018 USD ($) $ / shares	Oct. 31, 2019 $ / shares	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) $ / shares	Dec. 31, 2018 USD ($)	Nov. 30, 2019 $ / shares	Nov. 05, 2019 $ / shares	Oct. 29, 2019 $ / shares	May 31, 2019 $ / shares	Mar. 31, 2019 USD ($)	Oct. 22, 2018 USD ($)	Aug. 13, 2018 USD ($)
Debt Instrument [Line Items]
Borrowings under lines of credit									$ 3,696,000
Repayments of lines of credit									3,696,000
Debt issuance costs								$ 133,000	1,058,000
Shares issued, price per share | $ / shares						$ 0.5750
Common Stock | Underwritten Public Offering
Debt Instrument [Line Items]
Shares issued, price per share | $ / shares											$ 0.5750	$ 0.5750
Western Alliance Warrant
Debt Instrument [Line Items]
Initial exercise price of warrants | $ / shares				$ 2.13
SWK Warrants
Debt Instrument [Line Items]
Warrants expiration period			8 years
Warrants fair value assumptions, expected volatility rate			81.79%
Warrants fair value assumptions annual dividend per share | $ / shares			$ 0.00
Warrants fair value assumptions, risk-free interest rate			3.13%
Warrants, estimated fair value			$ 400,000
Warrants issued to purchase shares of common stock | shares			372,023
Warrants expire date			Nov. 09, 2026
Initial exercise price of warrants | $ / shares			$ 1.34					$ 1.00		$ 1.00
Warrants adjusted strike price | $ / shares						$ 1.00
Number of trading days of average closing price of common stock | Day			10
SWK Warrants | Warrants Issued on November 9, 2018
Debt Instrument [Line Items]
Initial exercise price of warrants | $ / shares			$ 1.34					0.8767
SWK Warrants | Warrants Issued on May, 2019
Debt Instrument [Line Items]
Initial exercise price of warrants | $ / shares								1.4197					$ 2.17
DPG Warrants
Debt Instrument [Line Items]
Warrants expiration period		8 years	8 years
Warrants fair value assumptions, expected volatility rate		80.73%	81.79%
Warrants fair value assumptions annual dividend per share | $ / shares		$ 0.00	$ 0.00
Warrants fair value assumptions, risk-free interest rate		2.37%	3.13%
Warrants, estimated fair value		$ 100,000	$ 300,000
Warrants issued to purchase shares of common stock | shares		34,552	279,851
Initial exercise price of warrants | $ / shares		$ 2.17	$ 1.34
Finder's fee			$ 500,000
Number of trading days of average closing price of common stock | Day		10	10
Warrants expiration period		7 years	7 years
DPG Warrants | Warrants Issued on November 9, 2018
Debt Instrument [Line Items]
Initial exercise price of warrants | $ / shares			$ 1.34					0.8767
DPG Warrants | Warrants Issued on May, 2019
Debt Instrument [Line Items]
Initial exercise price of warrants | $ / shares		$ 2.17						$ 1.4197
SWK Warrants and DPG Warrants
Debt Instrument [Line Items]
Warrants effective-interest method amortization period								5 years
Business Financing Agreement
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					$ 6,000,000
Line of credit facility expiration date					Mar. 06, 2020
Line of credit facility, interest rate description								Amounts outstanding under the Business Financing Agreement bore interest at a per annum floating rate equal to the greater of 4.5% or the “Prime Rate” published in the Money Rates section of the Western Edition of The Wall Street Journal (or such other rate of interest publicly announced from time to time by Western Alliance as its “Prime Rate”), plus 1.5% with respect to advances made under the line of credit, plus an additional 5.0% during any period that an event of default has occurred and is continuing.
Line of credit facility, commitment fee amount					$ 67,500
Line of credit facility, commitment fee description								the Company paid the first of two annual commitment fees totaling $67,500, being 0.25% of the aggregate $6.0 million commitment for the Domestic Revolver and 1.75% of the aggregate $3.0 million commitment for the EXIM Revolver. The commitment fees and the legal costs associated with acquiring the credit facilities were capitalized and were amortized on a straight-line basis as interest expense over the term of the Business Financing Agreement
Business Financing Agreement | Western Alliance Warrant
Debt Instrument [Line Items]
Warrants expiration period					10 years
Warrants fair value assumptions, expected volatility rate					91.49%
Warrants fair value assumptions annual dividend per share | $ / shares					$ 0.00
Warrants fair value assumptions, risk-free interest rate					2.88%
Warrants, estimated fair value					$ 100,000
Credit Agreement, First Amendment | SWK Warrants
Debt Instrument [Line Items]
Additional warrants to purchase common stock value		$ 200,000
Credit Agreement, First Amendment | DPG Warrants
Debt Instrument [Line Items]
Additional warrants to purchase common stock value		100,000
Additional finders fee		100,000
Maximum | SWK Warrants
Debt Instrument [Line Items]
Initial exercise price of warrants | $ / shares								$ 0.8767
Minimum | SWK Warrants
Debt Instrument [Line Items]
Initial exercise price of warrants | $ / shares								$ 1.34
Western Alliance | Business Financing Agreement
Debt Instrument [Line Items]
Line of credit facility minimum unrestricted cash covenant															$ 300,000
Interest expense including debt issuance costs			$ 100,000
Repayments of lines of credit			$ 900,000
Western Alliance | Business Financing Modification Agreement
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity				$ 2,500,000
Line of credit facility expiration date				Mar. 06, 2018
Line of credit, outstanding borrowings				$ 1,500,000
Line of credit facility default covenant advance																$ 1,500,000
Western Alliance Warrant
Debt Instrument [Line Items]
Warrants issued to purchase shares of common stock | shares				56,338
Warrants expire date				Sep. 27, 2028
Initial exercise price of warrants | $ / shares				$ 2.13
SWK Loan
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity														$ 12,500,000
Line of credit facility term			5 years
Borrowings under lines of credit			$ 12,500,000						$ 12,500,000
Debt instrument, repayment of interest-only on loan period			2 years
Debt instrument, principal repayments beginning term			2021
Repayments of lines of credit			$ 700,000
Debt instrument, maturity term			2023
Debt instrument covenant description								(i) maintain unencumbered liquid assets of (A) no less than $1.5 million or (B) the sum of aggregate cash flow from operations less capital expenditures, (ii) achieve certain revenue and EBITDA levels during the first two years of the loan, (iii) limit future borrowing, investments and dividends, and (iv) submit monthly and quarterly financial reporting. The Company was in compliance with these debt covenants as of December 31, 2018.
Debt issuance costs			$ 1,000,000
Loan origination fee			200,000
Finder's fee			400,000
Legal and other fees			$ 400,000
Interest expense								$ 2,200,000
Weighted-average interest rate								12.50%
SWK Loan | LIBOR
Debt Instrument [Line Items]
Line of credit facility bearing floating interest rate per annum			10.00%
Line of credit facility interest rate description								London Interbank Bank Offered Rate (“LIBOR”) plus 10% or another index that approximates LIBOR as close as possible if and when LIBOR no longer exists.
SWK Loan | Credit Agreement, First Amendment
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		15,000,000
Debt instrument covenant description								(a) adjust minimum revenue and EBITDA levels, (b) require the Company to have a shelf registration statement declared effective by the Securities and Exchange Commission before September 30, 2019, with a proposed maximum aggregate offering price of at least $10.0 million if the Company does not reach set minimum revenue levels for the three-month period ended September 30, 2019, and (c) require minimum liquidity of $1.5 million at all times. The First Amendment provides that if aggregate minimum revenue and EBITDA levels are not achieved by September 30, 2019, the minimum liquidity requirement will be increased to $3.0 million, until the Company has obtained additional equity or debt funding of no less than $5.0 million
Minimum level of liquidity financial covenant		1,500,000
Additional equity or debt funding requirement until minimum liquidity is met		5,000,000
Maximum aggregate offering price		10,000,000
Increase in minimum liquidity requirement if aggregate minimum revenue and EBITDA levels are not achieved		3,000,000
Financial covenant additional borrowings								$ 2,500,000
Loan origination and other fees to be paid		$ 100,000
SWK Loan | Credit Agreement, Second Amendment [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity							$ 5,000,000
SWK Loan | Maximum
Debt Instrument [Line Items]
Debt instrument covenants unencumbered liquid assets			$ 1,500,000
SWK Loan | Minimum | Credit Agreement, Second Amendment [Member]
Debt Instrument [Line Items]
Gross proceeds from subordinated debt threshold limit							$ 5,000,000
Loan Agreement | Pacific Mercantile Bank
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 3,000,000
Maximum borrowing base percentage of eligible accounts	90.00%
Maximum borrowing base percentage of eligible inventory	75.00%
Line of credit facility expiration date	Oct. 28, 2021
Interest rate	1.50%
Line of credit, outstanding borrowings								0
Line of credit facility, unused availability								$ 2,700,000
Loan Agreement | Pacific Mercantile Bank | Maximum
Debt Instrument [Line Items]
Interest rate	6.00%
Loan Agreement | Exim Bank
Debt Instrument [Line Items]
Line of credit facility expiration date	Oct. 28, 2020
Initial and annual fee	$ 52,500
Termination fee	$ 30,000
Domestic Revolving Credit Facility | Business Financing Agreement
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					$ 6,000,000
Maximum borrowing base percentage of eligible accounts receivable					75.00%
Line of credit facility commitment fee percentage					0.25%
Line of credit facility, commitment fee amount					$ 6,000,000
Export Revolving Credit Facility | Business Financing Agreement
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					$ 3,000,000
Maximum borrowing base percentage of eligible accounts receivable					85.00%
Line of credit facility commitment fee percentage					1.75%
Line of credit facility, commitment fee amount					$ 3,000,000
Line of Credit | Business Financing Agreement
Debt Instrument [Line Items]
Variable interest Rate with respect to advances made					1.50%
Line of credit facility interest rate during period in event of default					5.00%
Line of Credit | Minimum | Business Financing Agreement
Debt Instrument [Line Items]
Line of credit facility bearing floating interest rate per annum					4.50%