Stock-based Compensation - Expense (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 15,400,000	$ 14,800,000	$ 30,300,000	$ 30,200,000
Warrant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,600,000	600,000	2,500,000	600,000
Loss and loss adjustment expense, net
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	500,000	700,000	1,000,000.0	1,400,000
Other insurance expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	600,000	500,000	1,200,000	1,000,000.0
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	2,600,000	1,500,000	4,600,000	2,700,000
Technology development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	6,400,000	6,300,000	12,800,000	13,000,000.0
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 5,300,000	$ 5,800,000	$ 10,700,000	$ 12,100,000