Segment Information - Summary of Segment Information Reconciled to Consolidated Statements of Income (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Gross premiums earned	$ 181,124	$ 139,440	$ 360,049	$ 270,382
Reinsurance [Member]
Segment Reporting Information [Line Items]
Gross premiums earned	1,955	2,410	2,957	4,800
HCPCI [Member]
Segment Reporting Information [Line Items]
Gross premiums earned	$ 113,681	$ 100,440	$ 231,984	$ 202,571