INCOME TAXES - Principal Components of Net Deferred Tax Balances (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Compensation and other accrued expense	$ 111	$ 89
Benefits payable	89	79
Net operating loss carryforward	42	38
Deferred acquisition costs	22	17
Unearned revenues	8	9
Other	8	8
Capital loss carryforward	1	15
Investment securities	0	44
Total deferred income tax assets	281	299
Valuation allowance	(45)	(54)
Total deferred income tax assets, net of valuation allowance	236	245
Depreciable property and intangible assets	(329)	(273)
Investment securities	(181)	0
Prepaid expenses	(64)	(52)
Future policy benefits payable	(3)	(5)
Total deferred income tax liabilities	(577)	(330)
Total net deferred income tax liabilities	$ (341)	$ (85)