Related Party Transactions (Details)	12 Months Ended
	Dec. 31, 2022 $ / shares shares	Dec. 31, 2020 shares	Dec. 31, 2024 USD ($) director shares	Dec. 31, 2023 USD ($) shares
Related Party Transaction [Line Items]
Other assets			$ 42,400,000	$ 63,800,000
Other liabilities and accrued expenses			$ 105,700,000	$ 99,500,000
Affiliated entity | Lemonade, Inc. | The Lemonade Foundation
Related Party Transaction [Line Items]
Shares owned by foundation (in shares) | shares			400,000	400,000
Affiliated entity | The Lemonade Foundation
Related Party Transaction [Line Items]
Number of shared directors | director			2
Contribution to the Lemonade Foundation (in shares) | shares	500,000	500,000
Contribution of common stock to related party, fair value (usd per share) | $ / shares	$ 24.36
Other assets			$ 100,000	$ 0
Other liabilities and accrued expenses			$ 100,000	$ 0