BENEFITS PAYABLE - Benefit Expenses Excluded From Activity in Benefits Payable (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total future policy benefits	$ 0	$ (10)
Operating Segments | Individual Commercial
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total future policy benefits	0	(16)
Other Businesses
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total future policy benefits	$ 0	$ 6