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Concentration of Operations - Net Premiums Earned for the Top Ten States (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 270,639	$ 267,125	$ 271,698
Premium earned percentage	100.00%	100.00%	100.00%
Florida [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 38,976	$ 33,838	$ 31,955
Premium earned percentage	14.40%	12.70%	11.80%
Georgia [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 28,267	$ 30,504	$ 30,831
Premium earned percentage	10.40%	11.40%	11.30%
Pennsylvania [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 19,564	$ 19,963	$ 21,017
Premium earned percentage	7.20%	7.50%	7.70%
Louisiana [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 16,998	$ 21,150	$ 21,804
Premium earned percentage	6.30%	7.90%	8.00%
Illinois [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 16,294	$ 13,072	$ 12,209
Premium earned percentage	6.00%	4.90%	4.50%
North Carolina [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 15,863	$ 16,432	$ 17,883
Premium earned percentage	5.90%	6.20%	6.60%
Texas [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 10,886	$ 6,151	$ 6,307
Premium earned percentage	4.00%	2.30%	2.30%
Wisconsin [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 10,769	$ 11,724	$ 12,007
Premium earned percentage	4.00%	4.40%	4.40%
Virginia [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 10,151	$ 10,400	$ 11,537
Premium earned percentage	3.80%	3.80%	4.30%
South Carolina [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 8,603	$ 9,050	$ 9,808
Premium earned percentage	3.20%	3.40%	3.60%
All Others [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 94,268	$ 94,841	$ 96,340
Premium earned percentage	34.80%	35.50%	35.50%

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Premiums earned percentage.

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Schedule Of Premiums Earned Net By Segment [Line Items]

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Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums earned.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.12-17(Column E))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477965/944-235-S99-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 605
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479032/944-605-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(13)(c))
-SubTopic 220
-Topic 942
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(1))
-SubTopic 220
-Topic 944
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

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