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Stock Issued During Period, Issued For Charitable Contribution, Fair Value

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Noncash charitable contributions made by the entity during the period.

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Related Party Transactions (Details)		3 Months Ended			6 Months Ended
Related Party Transactions (Details)	Feb. 18, 2020 shares	Jun. 30, 2020 USD ($) director	Mar. 31, 2020 shares	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) director $ / shares	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Related Party Transaction [Line Items]
Due to (from) related parties		$ 0			$ 0		$ 0
Common share contribution to the Lemonade Foundation					12,200,000	$ 0
Common Stock
Related Party Transaction [Line Items]
Contribution to the Lemonade Foundation (shares) \| shares			500,000
Key stockholder \| Travel related expenses
Related Party Transaction [Line Items]
Expenses with related parties		$ 100,000		$ 100,000	$ 100,000	100,000
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
Contribution of common stock to related party, fair value (usd per share) \| $ / shares					$ 24.36
Common share contribution to the Lemonade Foundation					$ 12,200,000
Due from related party		$ 100,000			100,000
Affiliated entity \| Rental expense
Related Party Transaction [Line Items]
Expenses with related parties		$ 100,000		$ 100,000	$ 100,000	$ 100,000