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Related Party Transactions (Details)
$ / shares in Units, $ in Millions
3 Months Ended 9 Months Ended 12 Months Ended
Jan. 14, 2021
shares
Feb. 18, 2020
shares
Sep. 30, 2021
USD ($)
director
Sep. 30, 2020
USD ($)
Sep. 30, 2021
USD ($)
director
$ / shares
shares
Sep. 30, 2020
USD ($)
Dec. 31, 2020
USD ($)
Related Party Transaction [Line Items]              
Outstanding amounts from related parties     $ 0.0   $ 0.0   $ 0.0
Outstanding amounts to related parties     0.0   0.0   0.0
Common shares contribution to the Lemonade Foundation         0.0 $ 12.2  
Follow On Offering, Selling Shareholders              
Related Party Transaction [Line Items]              
Common stock sold (shares) | shares 1,524,314            
The Lemonade Foundation              
Related Party Transaction [Line Items]              
Outstanding amounts from related parties     0.0   0.0    
Outstanding amounts to related parties     0.0   0.0    
The Lemonade Foundation | Follow On Offering, Selling Shareholders              
Related Party Transaction [Line Items]              
Common stock sold (shares) | shares 100,000            
Key stockholder | Travel related expenses              
Related Party Transaction [Line Items]              
Expenses with related parties     $ 0.1 $ 0.1 $ 0.1 0.1  
Affiliated entity | The Lemonade Foundation              
Related Party Transaction [Line Items]              
Number of shared directors | director     2   2    
Contribution to the Lemonade Foundation (shares) | shares   500,000     500,000    
Contribution of common stock to related party, fair value (usd per share) | $ / shares         $ 24,360,000    
Common shares contribution to the Lemonade Foundation             $ 12.2
Affiliated entity | Rental expense              
Related Party Transaction [Line Items]              
Expenses with related parties     $ 0.1 $ 0.1 $ 0.1 $ 0.1