INCOME TAXES - DEFERRED ASSETS AND LIABILITIES (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Jan. 01, 2021	Dec. 31, 2020
Deferred tax assets:
Net federal operating loss carryforwards	$ 149.9	$ 166.0
Net state operating loss carryforwards	2.5	2.5
Insurance liabilities	329.4	298.5
Indirect costs allocable to self-constructed real estate assets	224.4	214.8
Accumulated other comprehensive loss	470.1	552.4
Other	0.0	7.3
Gross deferred tax assets	1,176.3	1,241.5
Deferred tax liabilities:
Investments	(34.8)	(37.2)
Present value of future profits and deferred acquisition costs	(152.1)	(148.9)
Other	(1.5)	0.0
Gross deferred tax liabilities	(188.4)	(186.1)
Net deferred tax assets	987.9	1,055.4
Current income taxes prepaid	0.2	8.0
Income tax assets, net	$ 988.1	$ 1,063.4	$ 806.4	$ 199.4