Stockholders’ Equity - Share-based Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 6.3	$ 7.0	$ 19.4	$ 22.6
Losses and loss adjustment expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	0.2	0.3	0.6	0.9
Insurance related expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	0.8	1.0	2.4	3.5
Technology and development expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	1.2	1.3	3.9	4.3
Sales and marketing expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	0.8	1.0	2.2	2.9
General and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 3.3	$ 3.4	$ 10.3	$ 11.0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details