FAIR VALUE OF FINANCIAL INSTRUMENTS - Financial Instruments Measured at Fair Value (Details) - USD ($)	Sep. 30, 2026	Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	$ 2,267,816,000	$ 2,205,350,000
US Treasury and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	91,495,000	104,104,000
States, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	173,420,000	261,734,000
Corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	819,339,000	783,154,000
Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	762,731,000	715,597,000
Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	164,413,000	145,407,000
Other asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	256,418,000	195,354,000
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	2,267,816,000	2,205,350,000
Money Market Accounts	62,576,000	44,751,000
Corporate-Owned Life Insurance	14,070,000	13,462,000
Total Assets Measured at Fair Value	2,344,462,000	2,263,563,000
Recurring \| US Treasury and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	91,495,000	104,104,000
Recurring \| States, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	173,420,000	261,734,000
Recurring \| Corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	819,339,000	783,154,000
Recurring \| Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	762,731,000	715,597,000
Recurring \| Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	164,413,000	145,407,000
Recurring \| Other asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	256,418,000	195,354,000
Recurring \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	31,064,000	26,568,000
Money Market Accounts	62,576,000	44,751,000
Corporate-Owned Life Insurance	0	0
Total Assets Measured at Fair Value	93,640,000	71,319,000
Recurring \| Level 1 \| US Treasury and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	31,064,000	26,568,000
Recurring \| Level 1 \| States, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	0	0
Recurring \| Level 1 \| Corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	0	0
Recurring \| Level 1 \| Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	0	0
Recurring \| Level 1 \| Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	0	0
Recurring \| Level 1 \| Other asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	0	0
Recurring \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	2,236,752,000	2,178,782,000
Money Market Accounts	0	0
Corporate-Owned Life Insurance	14,070,000	13,462,000
Total Assets Measured at Fair Value	2,250,822,000	2,192,244,000
Recurring \| Level 2 \| US Treasury and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	60,431,000	77,536,000
Recurring \| Level 2 \| States, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	173,420,000	261,734,000
Recurring \| Level 2 \| Corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	819,339,000	783,154,000
Recurring \| Level 2 \| Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	762,731,000	715,597,000
Recurring \| Level 2 \| Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	164,413,000	145,407,000
Recurring \| Level 2 \| Other asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	256,418,000	195,354,000
Recurring \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	0	0
Money Market Accounts	0	0
Corporate-Owned Life Insurance	0	0
Total Assets Measured at Fair Value	0	0
Recurring \| Level 3 \| US Treasury and government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	0	0
Recurring \| Level 3 \| States, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	0	0
Recurring \| Level 3 \| Corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	0	0
Recurring \| Level 3 \| Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	0	0
Recurring \| Level 3 \| Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	0	0
Recurring \| Level 3 \| Other asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fixed Maturity, Available-for-Sale	$ 0	$ 0

Fair value portion of asset recognized for present right to economic benefit.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of the amount that could be realized under a life insurance contract or contracts owned by the entity, commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

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Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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