FAIR VALUE MEASUREMENTS - Summary of Level 3 Fair Value Measurement Inputs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Fair Value Inputs Assets Quantitative Information [Line Items]
Asset fair value	$ 930,278	$ 949,413
Fixed maturities, available for sale	12,152,753	12,234,742
Significant unobservable inputs (Level 3)
Fair Value Inputs Assets Quantitative Information [Line Items]
Asset fair value	92,230	92,589
Fixed maturities, available for sale	147,223	$ 135,753
Significant unobservable inputs (Level 3) | Discounted cash flow | Other privately held investments
Fair Value Inputs Assets Quantitative Information [Line Items]
Asset fair value	$ 14,912
Significant unobservable inputs (Level 3) | Discounted cash flow | Minimum | Other privately held investments
Fair Value Inputs Assets Quantitative Information [Line Items]
Estimated maturity date (years)	0 years
Significant unobservable inputs (Level 3) | Discounted cash flow | Maximum | Other privately held investments
Fair Value Inputs Assets Quantitative Information [Line Items]
Estimated maturity date (years)	1 year
Significant unobservable inputs (Level 3) | Discounted cash flow | Weighted average | Other privately held investments
Fair Value Inputs Assets Quantitative Information [Line Items]
Estimated maturity date (years)	1 year
Significant unobservable inputs (Level 3) | Discounted cash flow | Discount rate | Other privately held investments
Fair Value Inputs Assets Quantitative Information [Line Items]
Unobservable input	0.057
Significant unobservable inputs (Level 3) | Discounted cash flow | Discount rate | Weighted average | Other privately held investments
Fair Value Inputs Assets Quantitative Information [Line Items]
Unobservable input	0.057
Significant unobservable inputs (Level 3) | Discounted cash flow | Default rate | Other privately held investments
Fair Value Inputs Assets Quantitative Information [Line Items]
Unobservable input	0.005
Significant unobservable inputs (Level 3) | Discounted cash flow | Default rate | Weighted average | Other privately held investments
Fair Value Inputs Assets Quantitative Information [Line Items]
Unobservable input	0.005
Significant unobservable inputs (Level 3) | Discounted cash flow | Loss absorption yield | Other privately held investments
Fair Value Inputs Assets Quantitative Information [Line Items]
Unobservable input	0.010
Significant unobservable inputs (Level 3) | Discounted cash flow | Loss absorption yield | Weighted average | Other privately held investments
Fair Value Inputs Assets Quantitative Information [Line Items]
Unobservable input	0.010
Significant unobservable inputs (Level 3) | Valuation, Market Approach | Other privately held investments
Fair Value Inputs Assets Quantitative Information [Line Items]
Asset fair value	$ 77,000