Overview and Basis of Presentation (Details)				3 Months Ended
	Nov. 08, 2021 USD ($) $ / shares	Feb. 09, 2021 USD ($) $ / shares shares	Sep. 08, 2020 USD ($) $ / shares shares	Mar. 31, 2021	Mar. 31, 2022 USD ($) state $ / shares	Dec. 31, 2021 USD ($) $ / shares
Business Description And Accounting Policies [Line Items]
Common stock, par value (in dollars per share) | $ / shares			$ 0.0001
Purchase price (in dollars per share) | $ / shares		$ 10.00
Other offering costs | $			$ 14,200,000
Underwriting fees | $			4,000,000
Deferred underwriting fees | $			$ 9,800,000
Business combination converted exchange ratio				1.01547844
Common stock par value (in dollars per share) | $ / shares					$ 0.0001	$ 0.0001
Sale of stock (in shares) | shares		17,000,000
Aggregate purchase price | $		$ 170,000,000
Number of states in which entity operates | state					8
Loss and LAE reserves | $					$ 76,900,000	$ 73,400,000
Lemonade, Inc.
Business Description And Accounting Policies [Line Items]
Common stock par value (in dollars per share) | $ / shares	$ 0.00001
Lemonade, Inc. | Metromile, Inc.
Business Description And Accounting Policies [Line Items]
Fully diluted equity value | $	$ 500,000,000
Equity value, net of unrestricted cash and cash equivalents | $	$ 340,000,000
Business combination converted exchange ratio	0.05263
Common stock par value (in dollars per share) | $ / shares	$ 0.00001
IPO
Business Description And Accounting Policies [Line Items]
Sale of stock (in shares) | shares			23,000,000
Other offering costs | $			$ 400,000
Over-Allotment Option
Business Description And Accounting Policies [Line Items]
Sale of stock (in shares) | shares			3,000,000
Purchase price (in dollars per share) | $ / shares			$ 10.00
Gross proceeds | $			$ 230,000,000
Private Placement
Business Description And Accounting Policies [Line Items]
Purchase price (in dollars per share) | $ / shares			$ 10.00
Sale of stock (in shares) | shares			540,000
Gross proceeds from private placement | $			$ 5,400,000
Sale per unit (in dollars per share) | $ / shares			$ 10.00
Common Class A
Business Description And Accounting Policies [Line Items]
Common stock, par value (in dollars per share) | $ / shares			0.0001
Class B Common Stock
Business Description And Accounting Policies [Line Items]
Share price (in dollars per share) | $ / shares			$ 0.0001
Share conversion ratio			1