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, 2024		Jun. 30, 2023		Jun. 30, 2024		Jun. 30, 2023
Segment Reporting Information [Line Items]
Gross premiums earned	$ 263,561	[1]	$ 181,946	[2]	$ 520,205	[3]	$ 362,014	[4]
Reinsurance [Member]
Segment Reporting Information [Line Items]
Gross premiums earned	6,655		4,915		12,766		9,450
HCPCI [Member]
Segment Reporting Information [Line Items]
Gross premiums earned	$ 143,702		$ 96,875		$ 292,973		$ 189,331

[1] Gross premiums earned under HCPCI Insurance Operations consist of $143,702 from HCPCI and $6,655 from a reinsurance company.

[2] Gross premiums earned under HCPCI Insurance Operations consist of $96,875 from HCPCI and $4,915 from a reinsurance company.

[3] Gross premiums earned under HCPCI Insurance Operations consist of $292,973 from HCPCI and $12,766 from a reinsurance company.

[4] Gross premiums earned under HCPCI Insurance Operations consist of $189,331 from HCPCI and $9,450 from a reinsurance company.