Losses and Loss Adjustment Expenses - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Reserves For Losses And Loss Adjustment Expenses [Line Items]
Claims and claim adjustment expenses overall development	$ 8,382	$ 4,607	$ 11,010	$ 8,438
Current year claims and claims adjustment expense	78,448	$ 51,310	148,524	$ 93,230
Weather Events [Member]
Reserves For Losses And Loss Adjustment Expenses [Line Items]
Current year claims and claims adjustment expense	5,811		11,932
United [Member]
Reserves For Losses And Loss Adjustment Expenses [Line Items]
Current year claims and claims adjustment expense	10,438		23,399
Accident Year 2021 and Prior [Member]
Reserves For Losses And Loss Adjustment Expenses [Line Items]
Claims and claim adjustment expenses overall development	$ 8,382		$ 11,010