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Summary of significant accounting policies - Derivative instruments- common stock warrants (Details) - shares | Jun. 22, 2023 | Dec. 31, 2023 | Jul. 31, 2023 | Jun. 22, 2022
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Warrant Exchange Offer |  |  |  |
Basin acquisition that met the definition of a business combination |  |  |  |
Warrants tendered (in shares) | 2,471,738 |  |  |
Number of warrants tendered (in shares) | 9,887,035 |  |  |
Shares of common stock underlying each warrant (in shares) | 0.25 |  |  | 0.25
Amended Warrant Agreement Offer |  |  |  |
Basin acquisition that met the definition of a business combination |  |  |  |
Shares of common stock underlying each warrant (in shares) | 0.225 | 0.225 | 0.225 | 0.225
Warrants outstanding (in shares) |  | 0 | 0 |

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