Stockholders' Equity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2020	Sep. 30, 2024	Dec. 31, 2023
Sale of Stock [Line Items]
Common stock, authorized (in shares)			200,000,000	200,000,000
Common stock, par value (usd per share)			$ 0.00001	$ 0.00001
Preferred stock, authorized (in shares)			10,000,000	10,000,000
Preferred stock, par value (usd per share)			$ 0.00001	$ 0.00001
Preferred stock, issued (in shares)			0	0
Omnibus Agreement
Sale of Stock [Line Items]
Class of warrant common stock exercise price (usd per share)	$ 0.01
Vesting period	5 years
Affiliated entity | The Lemonade Foundation | Lemonade, Inc.
Sale of Stock [Line Items]
Shares owned by foundation (in shares)			400,000	400,000
The Lemonade Foundation | Affiliated entity
Sale of Stock [Line Items]
Contribution to the Lemonade Foundation (in shares)		500,000