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Convertible Preferred Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions | 1 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2020 | May 31, 2020 | Oct. 31, 2018 | Apr. 30, 2017 | Mar. 31, 2021 | Feb. 28, 2021
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Convertible preferred stock, shares issued upon conversion | 16,079,230 |  |  |  |  | 16,079,230
Convertible preferred stock, shares issued | 12,958,452 |  |  |  | 0 |
Convertible preferred stock, par value | $ 0.0001 |  |  |  | $ 0.0001 |
Bridge Loan |  |  |  |  |  |
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Debt conversion to stock, aggregate debt plus accrued interest | $ 1.9 |  |  |  |  |
2020 Notes |  |  |  |  |  |
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Debt conversion to stock, aggregate debt plus accrued interest | $ 15.9 |  |  |  |  |
Series A convertible preferred stock |  |  |  |  |  |
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Convertible preferred stock, shares issued upon conversion | 2,857,142 |  |  |  |  |
Convertible preferred stock, shares issued | 2,857,142 |  |  | 2,089,285 |  |
Convertible preferred stock, par value |  |  |  | $ 10.50 |  |
Aggregate purchase price |  |  |  | $ 21.9 |  |
Series A convertible preferred stock | LAV Affiliate |  |  |  |  |  |
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Convertible preferred stock, shares issued | 767,857 |  |  |  |  |
Series A convertible preferred stock | Terns China |  |  |  |  |  |
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Proceeds from sale of convertible preferred stock |  |  |  | $ 8.0 |  |
Series B convertible preferred stock |  |  |  |  |  |
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Convertible preferred stock, shares issued upon conversion | 5,721,423 |  |  |  |  |
Convertible preferred stock, shares issued | 2,600,645 |  | 2,384,195 |  |  |
Convertible preferred stock, par value |  |  | $ 30.80 |  |  |
Aggregate purchase price |  |  | $ 73.4 |  |  |
Series B convertible preferred stock | LAV Affiliate |  |  |  |  |  |
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Convertible preferred stock, shares issued | 216,450 |  |  |  |  |
Series B convertible preferred stock | Terns China |  |  |  |  |  |
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Proceeds from sale of convertible preferred stock |  |  | $ 6.7 |  |  |
Series C convertible preferred stock |  |  |  |  |  |
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Convertible preferred stock, shares issued upon conversion | 7,500,665 |  |  |  |  |
Convertible preferred stock, shares issued | 7,500,665 |  |  |  |  |
Convertible preferred stock, par value | $ 11.65 |  |  |  |  |
Gross proceeds from issuance and conversion of convertible preferred stock | $ 87.4 |  |  |  |  |
Debt conversion, converted instrument, shares |  | 1,366,820 |  |  |  |
Series C convertible preferred stock | Bridge Loan |  |  |  |  |  |
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Debt conversion, converted instrument, shares | 167,159 |  |  |  |  |
Series C convertible preferred stock | 2020 Notes |  |  |  |  |  |
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Debt conversion, converted instrument, shares | 1,366,820 |  |  |  |  |
IPO |  |  |  |  |  |
Convertible Preferred Stock [Line Items] |  |  |  |  |  |
Convertible preferred stock, shares issued upon conversion |  |  |  |  |  | 16,079,230

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- Definition The number of securities classified as temporary equity that have been sold (or granted) to the entity's shareholders. Securities issued include securities outstanding and securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(27)(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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