BUSINESS SEGMENTS - SCHEDULE OF SELECTED FINANCIAL INFORMATION, BY SEGMENT (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Present value of future profits	$ 212.2	$ 222.6	$ 249.4	$ 275.4
Insurance Product Lines
Segment Reporting Information [Line Items]
Present value of future profits	212.2	222.6
Deferred acquisition costs	1,913.4	1,112.0
Insurance liabilities	27,361.6	26,112.8
Annuity | Insurance Product Lines
Segment Reporting Information [Line Items]
Present value of future profits	8.5	0.0
Deferred acquisition costs	655.1	126.4
Insurance liabilities	12,104.9	11,956.2
Health | Insurance Product Lines
Segment Reporting Information [Line Items]
Present value of future profits	189.7	205.9
Deferred acquisition costs	636.4	509.0
Insurance liabilities	9,642.1	9,508.7
Life | Insurance Product Lines
Segment Reporting Information [Line Items]
Present value of future profits	14.0	16.7
Deferred acquisition costs	615.9	473.3
Insurance liabilities	4,203.8	4,145.9
Investments not allocated to product lines | Insurance Product Lines
Segment Reporting Information [Line Items]
Present value of future profits	0.0	0.0
Deferred acquisition costs	6.0	3.3
Insurance liabilities	$ 1,410.8	$ 502.0