Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
less: Loss and loss adjustment expenses, net	$ 77.5		$ 70.5		$ 162.9	$ 136.4
Other insurance expense	21.4		18.8		47.5	36.1
Sales and marketing	59.6		36.8		102.8	67.2
Technology development	22.4		21.2		44.4	42.1
Depreciation and amortization					9.2	10.2
Income tax expense	1.3		2.1		2.3	4.2
Net loss	(43.9)	$ (62.4)	(57.2)	$ (47.3)	(106.3)	(104.5)
Domestic Tax Jurisdiction | CARES Act, ERC Program
Segment Reporting Information [Line Items]
Tax credits received under ERC program					11.7
Reportable Segment
Segment Reporting Information [Line Items]
Total revenue	164.1		122.0		315.3	241.1
less: Loss and loss adjustment expenses, net	77.5		70.5		162.9	136.4
Other insurance expense	21.4		18.8		47.5	36.1
Sales and marketing	9.9		11.0		15.0	21.6
Advertising expenses	49.7		25.8		87.8	45.6
Technology development	22.4		21.2		44.4	42.1
General and administrative	28.8		23.3		56.9	47.6
Interest expense	4.0		1.0		7.3	1.5
Depreciation and amortization	4.7		5.2		9.2	10.2
Other expenses	(11.7)		0.3		(11.7)	0.3
Income tax expense	1.3		2.1		2.3	4.2
Net loss	$ (43.9)		$ (57.2)		$ (106.3)	$ (104.5)