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v3.23.3

Related Party Transactions (Details) | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Sep. 30, 2023 USD ($) director employee | Sep. 30, 2022 USD ($) employee | Sep. 30, 2023 USD ($) employee director $ / shares shares | Sep. 30, 2022 USD ($) employee | Dec. 31, 2021 shares | Dec. 31, 2020 shares | Dec. 31, 2022 USD ($)
Related Party Transaction [Line Items] |  |  |  |  |  |  |
Due from related party | $ 67,600,000 |  | $ 67,600,000 |  |  |  | $ 75,200,000
Outstanding amounts due | $ 93,100,000 |  | $ 93,100,000 |  |  |  | $ 84,500,000
Immediate Family Member of Management or Principal Owner |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |
Number of stockholders | employee | 1 | 1 | 1 | 1 |  |  |
Travel expense (less than) | $ 100,000 | $ 100,000 | $ 100,000 | $ 100,000 |  |  |
Follow-on Offering, Selling Shareholders |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |
Common stock sold (in shares) | shares |  |  |  |  | 1,524,314 |  |
Related Party |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |
Number of shared directors | director | 2 |  | 2 |  |  |  |
Contribution to the Lemonade Foundation (in shares) | shares |  |  | 500,000 |  |  |  |
Contribution of common stock to related party, fair value (usd per share) | $ / shares |  |  | $ 24.36 |  |  |  |
Due from related party | $ 0 |  | $ 0 |  |  |  |
Outstanding amounts due | $ 0 |  | $ 0 |  |  |  |
Related Party | Follow-on Offering, Selling Shareholders |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |
Common stock sold (in shares) | shares |  |  |  |  |  | 100,000 |

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