INVESTMENTS - SUMMARY OF CARRYING VALUE AND ESTIMATED FAIR VALUE OF OUTSTANDING COMMERCIAL MORTGAGE LOANS AND UNDERLYING COLLATERAL (Details) $ in Millions	Mar. 31, 2025 USD ($)
Less than 60% \| Maximum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan to value ratio	60.00%
60% to less than 70% \| Maximum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan to value ratio	70.00%
60% to less than 70% \| Minimum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan to value ratio	60.00%
70% to less than 80% \| Maximum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan to value ratio	80.00%
70% to less than 80% \| Minimum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan to value ratio	70.00%
80% to less than 90% \| Maximum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan to value ratio	90.00%
80% to less than 90% \| Minimum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan to value ratio	80.00%
90% to less than 100% \| Maximum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan to value ratio	100.00%
90% to less than 100% \| Minimum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan to value ratio	90.00%
100% or greater \| Minimum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan to value ratio	100.00%
Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
2025	$ 54.2
2024	184.9
2023	305.5
2022	306.9
2021	139.5
Prior	548.7
Total amortized cost	1,539.7
Commercial mortgage loans	1,417.9
Collateral	4,213.5
Commercial Portfolio Segment \| Less than 60%
Financing Receivable, Credit Quality Indicator [Line Items]
2025	25.9
2024	153.6
2023	170.3
2022	143.9
2021	126.0
Prior	470.4
Total amortized cost	1,090.1
Commercial mortgage loans	1,012.1
Collateral	3,584.5
Commercial Portfolio Segment \| 60% to less than 70%
Financing Receivable, Credit Quality Indicator [Line Items]
2025	10.0
2024	31.3
2023	105.7
2022	24.3
2021	0.0
Prior	23.9
Total amortized cost	195.2
Commercial mortgage loans	185.5
Collateral	301.6
Commercial Portfolio Segment \| 70% to less than 80%
Financing Receivable, Credit Quality Indicator [Line Items]
2025	18.3
2024	0.0
2023	29.5
2022	77.6
2021	5.7
Prior	38.1
Total amortized cost	169.2
Commercial mortgage loans	148.4
Collateral	227.8
Commercial Portfolio Segment \| 80% to less than 90%
Financing Receivable, Credit Quality Indicator [Line Items]
2025	0.0
2024	0.0
2023	0.0
2022	61.1
2021	0.0
Prior	14.4
Total amortized cost	75.5
Commercial mortgage loans	64.3
Collateral	89.8
Commercial Portfolio Segment \| 90% to less than 100%
Financing Receivable, Credit Quality Indicator [Line Items]
2025	0.0
2024	0.0
2023	0.0
2022	0.0
2021	0.0
Prior	1.9
Total amortized cost	1.9
Commercial mortgage loans	1.4
Collateral	2.0
Commercial Portfolio Segment \| 100% or greater
Financing Receivable, Credit Quality Indicator [Line Items]
2025	0.0
2024	0.0
2023	0.0
2022	0.0
2021	7.8
Prior	0.0
Total amortized cost	7.8
Commercial mortgage loans	6.2
Collateral	$ 7.8

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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