DERIVATIVES - FAIR VALUE BY BALANCE SHEET LOCATION (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Fixed indexed call options
Derivatives, Fair Value [Line Items]
Fixed indexed call options	$ 297.2	$ 279.0
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Total assets	281.9	261.9
Not Designated as Hedging Instrument \| Fixed indexed call options \| Other invested assets
Derivatives, Fair Value [Line Items]
Fixed indexed call options	297.2	279.0
Not Designated as Hedging Instrument \| Reinsurance receivables \| Reinsurance receivables
Derivatives, Fair Value [Line Items]
Reinsurance receivables	(15.3)	(17.1)
Not Designated as Hedging Instrument \| Embedded derivatives related to fixed indexed annuities at fair value \| Policyholder account balances
Derivatives, Fair Value [Line Items]
Policyholder account balances	$ 1,598.4	$ 1,471.6

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Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangements

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