FAIR VALUE MEASUREMENTS - Changes in Level 3 for Financial Instruments (Details) - USD ($)	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening balance	$ 239,453,000	$ 228,342,000
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in net income	4,790,000	894,000
Included in OCI	668,000	(495,000)
Purchases	19,664,000	11,469,000
Sales	(670,000)	0
Settlements/ distributions	0	(12,494,000)
Closing balance	263,905,000	227,716,000
Change in unrealized gains/(losses)	4,790,000	1,728,000
Transfers out of Level 3 into Level 2	0	0
Fixed maturities, available for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening balance	147,223,000	135,753,000
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in net income	0	(834,000)
Included in OCI	668,000	(495,000)
Purchases	19,664,000	4,231,000
Sales	(670,000)	0
Settlements/ distributions	0	(12,180,000)
Closing balance	166,885,000	126,475,000
Change in unrealized gains/(losses)	0	0
Fixed maturities, available for sale | Corporate debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening balance	126,391,000	135,753,000
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in net income	0	(834,000)
Included in OCI	357,000	(495,000)
Purchases	7,664,000	4,231,000
Sales	(670,000)	0
Settlements/ distributions	0	(12,180,000)
Closing balance	133,742,000	126,475,000
Change in unrealized gains/(losses)	0	0
Fixed maturities, available for sale | ABS
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening balance	20,832,000	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in net income	0	0
Included in OCI	311,000	0
Purchases	12,000,000	0
Sales	0	0
Settlements/ distributions	0	0
Closing balance	33,143,000	0
Change in unrealized gains/(losses)	0	0
Other investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening balance	92,230,000	92,589,000
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in net income	4,790,000	1,728,000
Included in OCI	0	0
Purchases	0	7,238,000
Sales	0	0
Settlements/ distributions	0	(314,000)
Closing balance	97,020,000	101,241,000
Change in unrealized gains/(losses)	4,790,000	1,728,000
Other investments | CLO-Equities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening balance	0	5,300,000
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in net income	0	0
Included in OCI	0	0
Purchases	0	0
Sales	0	0
Settlements/ distributions	0	(314,000)
Closing balance	0	4,986,000
Change in unrealized gains/(losses)	0	0
Other investments | Other privately held investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening balance	92,230,000	87,289,000
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in net income	4,790,000	1,728,000
Included in OCI	0	0
Purchases	0	7,238,000
Sales	0	0
Settlements/ distributions	0	0
Closing balance	97,020,000	96,255,000
Change in unrealized gains/(losses)	$ 4,790,000	$ 1,728,000