INVESTMENTS (GROSS UNREALIZED LOSSES) (Details) $ in Millions	Jun. 30, 2017 USD ($) securities	Dec. 31, 2016 USD ($) securities
Investments, Debt and Equity Securities [Abstract]
Number of fixed maturities in an unrealized loss position greater than 12 months | securities	634	794
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	$ 8,402	$ 9,702
Less Than 12 Months, Gross Unrealized Losses	(458)	(754)
Greater than 12 Months, Fair Value	568	652
Greater Than 12 Months, Gross Unrealized Losses	(62)	(105)
Total, Fair Value	8,970	10,354
Total, Gross Unrealized Losses	(520)	(859)
Public corporate
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	2,032	2,455
Less Than 12 Months, Gross Unrealized Losses	(40)	(75)
Greater than 12 Months, Fair Value	149	113
Greater Than 12 Months, Gross Unrealized Losses	(5)	(6)
Total, Fair Value	2,181	2,568
Total, Gross Unrealized Losses	(45)	(81)
Private corporate
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	1,108	1,483
Less Than 12 Months, Gross Unrealized Losses	(26)	(38)
Greater than 12 Months, Fair Value	155	277
Greater Than 12 Months, Gross Unrealized Losses	(18)	(17)
Total, Fair Value	1,263	1,760
Total, Gross Unrealized Losses	(44)	(55)
U.S. Treasury, government and agency
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	5,153	5,356
Less Than 12 Months, Gross Unrealized Losses	(386)	(624)
Greater than 12 Months, Fair Value	0	0
Greater Than 12 Months, Gross Unrealized Losses	0	0
Total, Fair Value	5,153	5,356
Total, Gross Unrealized Losses	(386)	(624)
State and Political Sub- divisions
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	0	0
Less Than 12 Months, Gross Unrealized Losses	0	0
Greater than 12 Months, Fair Value	19	18
Greater Than 12 Months, Gross Unrealized Losses	(1)	(2)
Total, Fair Value	19	18
Total, Gross Unrealized Losses	(1)	(2)
Foreign Govts
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	46	73
Less Than 12 Months, Gross Unrealized Losses	(1)	(3)
Greater than 12 Months, Fair Value	35	49
Greater Than 12 Months, Gross Unrealized Losses	(5)	(11)
Total, Fair Value	81	122
Total, Gross Unrealized Losses	(6)	(14)
Commercial Mortgage- backed
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	39	66
Less Than 12 Months, Gross Unrealized Losses	(5)	(5)
Greater than 12 Months, Fair Value	171	171
Greater Than 12 Months, Gross Unrealized Losses	(31)	(67)
Total, Fair Value	210	237
Total, Gross Unrealized Losses	(36)	(72)
Residential Mortgage- backed
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	13	47
Less Than 12 Months, Gross Unrealized Losses	0	0
Greater than 12 Months, Fair Value	19	4
Greater Than 12 Months, Gross Unrealized Losses	0	0
Total, Fair Value	32	51
Total, Gross Unrealized Losses	0	0
Asset- backed
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	3	4
Less Than 12 Months, Gross Unrealized Losses	0	0
Greater than 12 Months, Fair Value	8	8
Greater Than 12 Months, Gross Unrealized Losses	(1)	(1)
Total, Fair Value	11	12
Total, Gross Unrealized Losses	(1)	(1)
Redeemable Preferred Stock
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	8	218
Less Than 12 Months, Gross Unrealized Losses	0	(9)
Greater than 12 Months, Fair Value	12	12
Greater Than 12 Months, Gross Unrealized Losses	(1)	(1)
Total, Fair Value	20	230
Total, Gross Unrealized Losses	$ (1)	$ (10)