Cover - shares	9 Months Ended
	Sep. 30, 2022	Nov. 08, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2022
Document Transition Report	false
Entity File Number	001-39367
Entity Registrant Name	Lemonade, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	32-0469673
Entity Address, Address Line One	5 Crosby Street, 3rd Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10013
City Area Code	844
Local Phone Number	733-8666
Title of 12(b) Security	Common Stock, $0.00001 par value per share
Trading Symbol	LMND
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		69,163,813
Amendment Flag	false
Entity Central Index Key	0001691421
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3