Losses and Loss Adjustment Expenses - Schedule of Incurred and Paid Claims Development (Detail) $ in Thousands		Dec. 31, 2023 USD ($) Account	Dec. 31, 2022 USD ($)		Dec. 31, 2021 USD ($)		Dec. 31, 2020 USD ($)		Dec. 31, 2019 USD ($)		Dec. 31, 2018 USD ($)		Dec. 31, 2017 USD ($)		Dec. 31, 2016 USD ($)		Dec. 31, 2015 USD ($)		Dec. 31, 2014 USD ($)
Homeowners Multi-peril and Dwelling Fire Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	$ 1,411,970
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	1,193,014
All outstanding liabilities before 2014, net of reinsurance		37
Liabilities for loss and LAE, net of reinsurance		218,993
Homeowners Wind-only Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		15,020
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		11,447
Liabilities for loss and LAE, net of reinsurance		3,573
Losses Specific To Any Hurricane And Storm Events Prior To 2023 [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		244,456
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		212,683
Liabilities for loss and LAE, net of reinsurance		31,773
Accident Year 2014 [Member] | Homeowners Multi-peril and Dwelling Fire Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	93,298	$ 93,358		$ 93,181		$ 92,945		$ 92,454		$ 90,084		$ 88,053		$ 84,917		$ 81,773		$ 75,810
Total of IBNR Plus Expected Development Reported Claims	[1]	$ 93
Cumulative Number of Reported Claims | Account	[1]	7,662
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	$ 93,205	92,986		92,924		92,264		90,707		87,125		82,463		77,712		68,897		$ 47,650
Accident Year 2015 [Member] | Homeowners Multi-peril and Dwelling Fire Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	103,818	103,671		103,135		102,587		102,149		101,272		96,173		90,902		78,017
Total of IBNR Plus Expected Development Reported Claims	[1]	$ 250
Cumulative Number of Reported Claims | Account	[1]	7,665
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	$ 103,569	103,405		102,486		101,424		99,200		95,179		87,784		76,042		50,939
Accident Year 2015 [Member] | Homeowners Wind-only Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		582	582	[2]	582	[2]	582	[2]	605	[2]	692	[2]	569	[2]	401	[2]	308	[2]
Total of IBNR Plus Expected Development Reported Claims	[2]	$ 0
Cumulative Number of Reported Claims | Account	[2]	100
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 582	582	[2]	582	[2]	582	[2]	582	[2]	582	[2]	465	[2]	332	[2]	$ 156	[2]
Accident Year 2016 [Member] | Homeowners Multi-peril and Dwelling Fire Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	92,779	92,738		92,333		92,752		92,986		92,684		90,879		81,446
Total of IBNR Plus Expected Development Reported Claims	[1]	$ 174
Cumulative Number of Reported Claims | Account	[1]	6,936
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	$ 92,605	92,367		92,001		90,989		89,144		83,311		73,037		51,663
Accident Year 2016 [Member] | Homeowners Wind-only Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		1,957	1,948	[2]	2,255	[2]	1,837	[2]	1,853	[2]	1,814	[2]	1,314	[2]	1,005	[2]
Total of IBNR Plus Expected Development Reported Claims	[2]	$ 4
Cumulative Number of Reported Claims | Account	[2]	228
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 1,952	1,944	[2]	1,843	[2]	1,821	[2]	1,772	[2]	1,405	[2]	1,155	[2]	689	[2]
Accident Year 2016 [Member] | Losses Specific To Any Hurricane And Storm Events Prior To 2023 [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		27,634	27,634		27,634		27,634		28,133		26,211		24,126		21,414
Total of IBNR Plus Expected Development Reported Claims		$ 464
Cumulative Number of Reported Claims | Account		2,420
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 27,169	27,146		26,807		26,098		25,849		23,316		20,025		$ 12,227
Accident Year 2017 [Member] | Homeowners Multi-peril and Dwelling Fire Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	91,132	90,652		90,877		90,958		89,652		88,937		91,443
Total of IBNR Plus Expected Development Reported Claims	[1]	$ 640
Cumulative Number of Reported Claims | Account	[1]	5,776
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	$ 90,492	89,387		86,364		83,383		78,808		66,996		43,039
Accident Year 2017 [Member] | Homeowners Wind-only Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		807	991	[2]	923	[2]	792	[2]	815	[2]	1,119	[2]	1,529	[2]
Total of IBNR Plus Expected Development Reported Claims	[2]	$ 16
Cumulative Number of Reported Claims | Account	[2]	157
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 792	792	[2]	792	[2]	792	[2]	789	[2]	786	[2]	484	[2]
Accident Year 2017 [Member] | Losses Specific To Any Hurricane And Storm Events Prior To 2023 [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		53,649	53,636		53,628		53,624		53,557		54,080		53,602
Total of IBNR Plus Expected Development Reported Claims		$ 236
Cumulative Number of Reported Claims | Account		21,777
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 53,413	53,634		53,216		49,425		47,524		47,514		$ 43,905
Accident Year 2018 [Member] | Homeowners Multi-peril and Dwelling Fire Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	83,126	82,816		83,234		83,123		83,976		79,436
Total of IBNR Plus Expected Development Reported Claims	[1]	$ 2,330
Cumulative Number of Reported Claims | Account	[1]	4,771
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	$ 80,796	79,247		76,311		71,809		63,958		41,014
Accident Year 2018 [Member] | Homeowners Wind-only Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		1,037	1,226	[2]	1,109	[2]	1,061	[2]	708	[2]	798	[2]
Total of IBNR Plus Expected Development Reported Claims	[2]	$ 69
Cumulative Number of Reported Claims | Account	[2]	137
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 967	925	[2]	899	[2]	745	[2]	607	[2]	216	[2]
Accident Year 2018 [Member] | Losses Specific To Any Hurricane And Storm Events Prior To 2023 [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		16,466	16,476		16,532		16,532		16,532		16,543
Total of IBNR Plus Expected Development Reported Claims		$ 0
Cumulative Number of Reported Claims | Account		1,719
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 16,466	16,476		16,477		16,436		15,992		$ 13,391
Accident Year 2019 [Member] | Homeowners Multi-peril and Dwelling Fire Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	101,081	99,754		96,821		94,018		95,467
Total of IBNR Plus Expected Development Reported Claims	[1]	$ 5,788
Cumulative Number of Reported Claims | Account	[1]	5,402
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	$ 95,293	91,839		81,941		70,182		47,471
Accident Year 2019 [Member] | Homeowners Wind-only Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		1,909	2,359	[2]	1,833	[2]	1,501	[2]	1,132	[2]
Total of IBNR Plus Expected Development Reported Claims	[2]	$ 115
Cumulative Number of Reported Claims | Account	[2]	154
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 1,794	1,770	[2]	1,451	[2]	1,290	[2]	$ 828	[2]
Accident Year 2019 [Member] | Losses Specific To Any Hurricane And Storm Events Prior To 2023 [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		0
Total of IBNR Plus Expected Development Reported Claims		$ 0
Cumulative Number of Reported Claims | Account		144
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 0
Accident Year 2020 [Member] | Homeowners Multi-peril and Dwelling Fire Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	170,175	159,758		133,349		126,086
Total of IBNR Plus Expected Development Reported Claims	[1]	$ 8,214
Cumulative Number of Reported Claims | Account	[1]	8,264
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	$ 161,961	144,298		108,388		56,173
Accident Year 2020 [Member] | Homeowners Wind-only Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		3,036	3,386	[2]	1,970	[2]	1,621	[2]
Total of IBNR Plus Expected Development Reported Claims	[2]	$ 280
Cumulative Number of Reported Claims | Account	[2]	193
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 2,756	2,435	[2]	1,461	[2]	567	[2]
Accident Year 2020 [Member] | Losses Specific To Any Hurricane And Storm Events Prior To 2023 [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		61,847	55,235		46,284		30,264
Total of IBNR Plus Expected Development Reported Claims		$ 7,491
Cumulative Number of Reported Claims | Account		3,294
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 54,356	47,056		34,771		$ 14,964
Accident Year 2021 [Member] | Homeowners Multi-peril and Dwelling Fire Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	186,059	186,606		187,164
Total of IBNR Plus Expected Development Reported Claims	[1]	$ 21,921
Cumulative Number of Reported Claims | Account	[1]	11,787
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	$ 164,138	142,054		85,895
Accident Year 2021 [Member] | Homeowners Wind-only Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		1,556	1,257	[2]	682	[2]
Total of IBNR Plus Expected Development Reported Claims	[2]	$ 396
Cumulative Number of Reported Claims | Account	[2]	114
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 1,161	799	[2]	415	[2]
Accident Year 2021 [Member] | Losses Specific To Any Hurricane And Storm Events Prior To 2023 [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		13,000	13,000		11,689
Total of IBNR Plus Expected Development Reported Claims		$ 348
Cumulative Number of Reported Claims | Account		2,597
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 12,652	12,616		$ 9,323
Accident Year 2022 [Member] | Homeowners Multi-peril and Dwelling Fire Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	257,683	263,626
Total of IBNR Plus Expected Development Reported Claims	[1]	$ 52,895
Cumulative Number of Reported Claims | Account	[1]	13,393
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	$ 204,788	135,793
Accident Year 2022 [Member] | Homeowners Wind-only Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		1,943	1,284	[2]
Total of IBNR Plus Expected Development Reported Claims	[2]	$ 830
Cumulative Number of Reported Claims | Account	[2]	136
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 1,113	704	[2]
Accident Year 2022 [Member] | Losses Specific To Any Hurricane And Storm Events Prior To 2023 [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		71,860	65,325
Total of IBNR Plus Expected Development Reported Claims		$ 23,233
Cumulative Number of Reported Claims | Account		13,992
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 48,627	$ 32,998
Accident Year 2023 [Member] | Homeowners Multi-peril and Dwelling Fire Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	232,819
Total of IBNR Plus Expected Development Reported Claims	[1]	$ 126,652
Cumulative Number of Reported Claims | Account	[1]	7,554
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance	[1]	$ 106,167
Accident Year 2023 [Member] | Homeowners Wind-only Insurance [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		2,193
Total of IBNR Plus Expected Development Reported Claims	[2]	$ 1,862
Cumulative Number of Reported Claims | Account	[2]	94
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 330
Accident Year 2023 [Member] | Losses Specific To Any Hurricane And Storm Events Prior To 2023 [Member]
Claims Development [Line Items]
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		0
Total of IBNR Plus Expected Development Reported Claims		$ 0
Cumulative Number of Reported Claims | Account		272
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance		$ 0

[1] Excludes losses from Wind-only insurance (2014 through 2023) and any hurricane and storm events prior to 2023.

[2] Excludes losses from multi-peril and dwelling fire insurance (2014 through 2023) and any hurricane and storm events prior to 2023.