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The Company and its Significant Accounting Policies - Additional Information (Details) |  |  |  |  | 1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | ---
May 22, 2019 USD ($) $ / shares shares | May 14, 2019 $ / shares shares | Jan. 01, 2019 USD ($) | Nov. 02, 2018 | Sep. 30, 2019 USD ($) Employee | Nov. 30, 2018 | Jun. 30, 2020 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2019 USD ($) Segment shares | Dec. 31, 2018 USD ($) Customer shares
Company And Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |
Cash and cash equivalents |  |  |  |  |  |  |  | $ 11,298,000 | $ 11,298,000 | $ 13,049,000
Net proceeds from issuance of IPO |  |  |  |  |  |  |  |  | 36,864,000 |
Cash and investment for operating activities |  |  |  |  |  |  |  |  | 33,523,000 | (3,861,000)
Reverse stock split ratio |  |  |  | 0.0667 |  | 0.0667 |  |  |  |
Allowance for credit losses |  |  |  |  |  |  |  | 52,000 | 52,000 | 11,000
Bad debt expense recognized |  |  |  |  |  |  |  |  | $ 45,000 | 5,000
Number of reporting segment | Segment |  |  |  |  |  |  |  |  | 1 |
Foreign cash and cash equivalents |  |  |  |  |  |  |  | 733,000 | $ 733,000 | $ 884,000
Number of customers | Customer |  |  |  |  |  |  |  |  |  | 2
Revenue |  |  |  |  |  |  |  |  | 116,251,000 | $ 135,665,000
Revenue recognition upon achievement of milestones |  |  |  |  |  |  |  |  |  | 0
Advertising expenses |  |  |  |  |  |  |  |  | 35,000 | 27,000
Trade-in guarantee liability |  |  |  |  |  |  |  | 0 | 0 | 268,000
Revenue recognized, trade-in guarantee |  |  |  |  |  |  |  |  | 268,000 | 537,000
Net foreign currency transactions losses |  |  |  |  |  |  |  |  | 543,000 | 549,000
Number of employees reduced related to restructuring activities | Employee |  |  |  |  | 16 |  |  |  |  |
Restructuring costs |  |  |  |  | $ 747,000 |  |  |  | 736,000 |
Restructuring charges paid |  |  |  |  |  |  |  | 209,000 |  |
IPO closing date |  | May 14, 2019 |  |  |  |  |  |  |  |
Unpaid issuance costs and charged to accounts payable or accrued expenses |  |  |  |  |  |  |  | 14,000 | 14,000 |
Deferred revenue as contract liabilities |  |  | $ 770,000 |  |  |  |  | 291,000 | 291,000 | 4,223,000
ASC 606 |  |  |  |  |  |  |  |  |  |
Company And Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative effect adjustment net of associated tax effect to reduce accumulated deficit |  |  | 3,115,000 |  |  |  |  |  |  |
Cumulative effect adjustment associated tax effect to reduce accumulated deficit |  |  | 215,000 |  |  |  |  |  |  |
Deferred revenue as contract liabilities |  |  | $ 770,000 |  |  |  |  |  |  |
Forecast |  |  |  |  |  |  |  |  |  |
Company And Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |
Restructuring costs |  |  |  |  |  |  | $ 527,000 |  |  |
Customer A and B |  |  |  |  |  |  |  |  |  |
Company And Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  |  | 4,168,000
Non-Recurring Engineering Tooling and Purchased Software Licenses |  |  |  |  |  |  |  |  |  |
Company And Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |
Amortization costs |  |  |  |  |  |  |  |  | 2,904,000 | 1,410,000
Net book value |  |  |  |  |  |  |  | 630,000 | 630,000 | $ 1,686,000
Deferred costs |  |  |  |  |  |  |  | 4,524,000 | $ 4,524,000 |
Common Stock |  |  |  |  |  |  |  |  |  |
Company And Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |
Shares issued and sold | shares |  |  |  |  |  |  |  |  | 228,294 | 1,270,905
Offering expenses paid |  |  |  |  |  |  |  |  | $ 30,000 | $ 831,000
Common Stock | IPO |  |  |  |  |  |  |  |  |  |
Company And Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |
Net proceeds from issuance of IPO | $ 36,850,000 |  |  |  |  |  |  |  | $ 36,850,000 |
Shares issued and sold | shares | 505,714 | 3,571,429 |  |  |  |  |  |  | 4,297,901 |
Shares issued and sold, price per share | $ / shares | $ 11.00 | $ 11.00 |  |  |  |  |  |  |  |
Underwriting discounts and commissions | $ 3,139,000 |  |  |  |  |  |  |  |  |
Offering expenses paid | $ 4,861,000 |  |  |  |  |  |  |  | $ 8,000,000 |
Deferred offering costs |  |  |  |  |  |  |  | $ 63,000 | $ 63,000 | $ 4,861,000
Common Stock | Over-Allotment |  |  |  |  |  |  |  |  |  |
Company And Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |
Shares issued and sold | shares | 30,000 |  |  |  |  |  |  |  |  |
Shares issued and sold, price per share | $ / shares | $ 11.00 |  |  |  |  |  |  |  |  |

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