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Income Taxes - Additional Information (Details) - USD ($) | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2019 | Dec. 31, 2019 | Dec. 31, 2018
Income Tax [Line Items] |  |  |
Deferred tax assets generated from foreign NOLs |  | $ 67,000 | $ 127,000
Net balance of deferred tax asset |  | 3,700,000 | 5,200,000
Deferred tax asset, valuation allowance | $ 400,000 | 388,000 | 5,097,000
U.S. deferred tax assets from operations | 700,000 | $ 1,322,000 | $ 616,000
Deferred tax assets and related valuation allowance written off | 700,000 |  |
U.S. deferred tax assets, realizable portion of valuation allowance | $ 3,300,000 |  |
Earliest Tax Year [Member] |  |  |
Income Tax [Line Items] |  |  |
Tax credits expiration year |  | 2020 |
Latest Tax Year [Member] |  |  |
Income Tax [Line Items] |  |  |
Tax credits expiration year |  | 2024 |
Research and Development Credit Carryforwards [Member] |  |  |
Income Tax [Line Items] |  |  |
Tax credit carryforward amount |  | $ 1,724,000 |
Research and Development Credit Carryforwards [Member] | Earliest Tax Year [Member] |  |  |
Income Tax [Line Items] |  |  |
Tax credit carryforwards expiration year |  | 2020 |
Research and Development Credit Carryforwards [Member] | Latest Tax Year [Member] |  |  |
Income Tax [Line Items] |  |  |
Tax credit carryforwards expiration year |  | 2038 |
Federal [Member] |  |  |
Income Tax [Line Items] |  |  |
Net operating loss carryforwards |  | $ 5,565,000 |
Operating loss carryforwards expiration year |  | 2038 |
State [Member] |  |  |
Income Tax [Line Items] |  |  |
Net operating loss carryforwards |  | $ 6,680,000 |

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