INVESTMENTS - SUMMARY OF WEIGHTED AVERAGE LOAN-TO-VALUE RATIO FOR OUTSTANDING MORTGAGE LOANS (Details) $ in Millions	Dec. 31, 2024 USD ($)
Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
2024	$ 185.2
2023	305.8
2022	308.0
2021	139.9
2020	37.5
Prior	525.0
Total amortized cost	1,501.4
Mortgage loans	1,344.2
Collateral	4,799.3
Less than 60% \| Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
2024	153.9
2023	170.6
2022	130.1
2021	134.1
2020	37.5
Prior	443.4
Total amortized cost	1,069.6
Mortgage loans	962.1
Collateral	$ 4,189.1
Less than 60% \| Maximum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan-to-value ratio	60.00%
60% to less than 70% \| Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
2024	$ 31.3
2023	92.9
2022	39.1
2021	5.8
2020	0.0
Prior	28.5
Total amortized cost	197.6
Mortgage loans	181.2
Collateral	$ 304.6
60% to less than 70% \| Minimum
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%
70% to less than 80% \| Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
2024	$ 0.0
2023	42.3
2022	77.6
2021	0.0
2020	0.0
Prior	38.5
Total amortized cost	158.4
Mortgage loans	139.2
Collateral	$ 214.6
70% to less than 80% \| Minimum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan-to-value ratio	70.00%
70% to less than 80% \| Maximum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan-to-value ratio	80.00%
80% to less than 90% \| Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
2024	$ 0.0
2023	0.0
2022	61.2
2021	0.0
2020	0.0
Prior	0.0
Total amortized cost	61.2
Mortgage loans	51.7
Collateral	$ 75.9
80% to less than 90% \| Minimum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan-to-value ratio	80.00%
80% to less than 90% \| Maximum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan-to-value ratio	90.00%
90% or greater \| Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
2024	$ 0.0
2023	0.0
2022	0.0
2021	0.0
2020	0.0
Prior	14.6
Total amortized cost	14.6
Mortgage loans	10.0
Collateral	$ 15.1
90% or greater \| Minimum
Financing Receivable, Credit Quality Indicator [Line Items]
Loan-to-value ratio	90.00%

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Amortized cost of financing receivable originated more than five years prior to current fiscal year. Excludes net investment in lease.

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