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Stockholders' Equity (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Jan. 14, 2021
Jul. 02, 2020
Jul. 01, 2020
Feb. 18, 2020
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2021
Jul. 07, 2020
Sale of Stock [Line Items]                
Conversion of convertible preferred stock to common stock upon closing of Initial Public Offering (IPO) (in shares)   31,557,107 31,557,107   31,557,107      
Common stock, authorized (shares)         200,000,000   200,000,000 200,000,000
Common stock, par value (usd per share)         $ 0.00001   $ 0.00001 $ 0.00001
Preferred stock, authorized (shares)               10,000,000
Preferred stock, par value (usd per share)               $ 0.00001
Preferred Stock, Shares Outstanding             0  
Preferred Stock, Shares Issued             0  
The Lemonade Foundation | Affiliated entity                
Sale of Stock [Line Items]                
Contribution to the Lemonade Foundation (in shares)       500,000 500,000      
IPO                
Sale of Stock [Line Items]                
Common stock sold (shares)   12,650,000            
Common stock sold, price (usd per share)   $ 29            
Net proceeds from sale   $ 335.6            
Offering costs, expensed           $ 3.5    
Underwriter's option                
Sale of Stock [Line Items]                
Common stock sold (shares) 718,647 1,650,000            
Net proceeds from sale $ 114.6              
Follow On Offering                
Sale of Stock [Line Items]                
Common stock sold (shares) 3,300,000              
Net proceeds from sale $ 525.7              
Follow On Offering, Selling Shareholders                
Sale of Stock [Line Items]                
Common stock sold (shares) 1,524,314              
Follow On Offering, Selling Shareholders | The Lemonade Foundation                
Sale of Stock [Line Items]                
Common stock sold (shares) 100,000