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Loans Payable - Additional Information (Details) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2020 | May 31, 2020 | Mar. 31, 2021 | Dec. 29, 2020 | Oct. 31, 2018 | Apr. 30, 2017
Short Term Debt [Line Items] |  |  |  |  |  |
Debt Instrument, fair value |  |  | $ 0 |  |  |
Convertible preferred stock, shares issued | 12,958,452 |  | 0 |  |  |
Bridge Loan |  |  |  |  |  |
Short Term Debt [Line Items] |  |  |  |  |  |
Debt Instrument, fair value | $ 2,100 |  |  |  |  |
Proceeds from issuance of debt |  | $ 1,800 |  |  |  |
Debt instrument, interest rate |  | 10.00% |  |  |  |
Debt conversion, original debt, amount | 1,800 |  |  |  |  |
Proceeds from debt payable in different currency, description |  |  | payable in renminbi (RMB) at an established USD/RMB exchange rate, based on an average of the previous five working days before May 8, 2020. |  |  |
Debt conversion to stock, aggregate debt plus accrued interest | $ 1,900 |  |  |  |  |
Debt conversion, accrued interest, amount |  |  |  | $ 100 |  |
Series C convertible preferred stock |  |  |  |  |  |
Short Term Debt [Line Items] |  |  |  |  |  |
Debt conversion, converted instrument, shares |  | 1,366,820 |  |  |  |
Convertible preferred stock, shares issued | 7,500,665 |  |  |  |  |
Series C convertible preferred stock | Bridge Loan |  |  |  |  |  |
Short Term Debt [Line Items] |  |  |  |  |  |
Debt conversion, converted instrument, shares | 167,159 |  |  |  |  |
Series A convertible preferred stock |  |  |  |  |  |
Short Term Debt [Line Items] |  |  |  |  |  |
Convertible preferred stock, shares issued | 2,857,142 |  |  |  |  | 2,089,285
Series A convertible preferred stock | LAV Affiliate |  |  |  |  |  |
Short Term Debt [Line Items] |  |  |  |  |  |
Convertible preferred stock, shares issued | 767,857 |  |  |  |  |
Series B convertible preferred stock |  |  |  |  |  |
Short Term Debt [Line Items] |  |  |  |  |  |
Convertible preferred stock, shares issued | 2,600,645 |  |  |  | 2,384,195 |
Series B convertible preferred stock | LAV Affiliate |  |  |  |  |  |
Short Term Debt [Line Items] |  |  |  |  |  |
Convertible preferred stock, shares issued | 216,450 |  |  |  |  |
2020 Notes |  |  |  |  |  |
Short Term Debt [Line Items] |  |  |  |  |  |
Proceeds from issuance of debt |  | $ 15,000 |  |  |  |
Debt instrument, interest rate |  | 10.00% |  |  |  |
Debt conversion, original debt, amount |  | $ 15,900 |  |  |  |
Debt conversion to stock, aggregate debt plus accrued interest | $ 15,900 |  |  |  |  |
2020 Notes | Series C convertible preferred stock |  |  |  |  |  |
Short Term Debt [Line Items] |  |  |  |  |  |
Debt conversion, converted instrument, shares | 1,366,820 |  |  |  |  |

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