INVESTMENTS (GROSS UNREALIZED LOSSES) (Details) $ in Millions	Mar. 31, 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	769	794
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	$ 8,561	$ 9,702
Less Than 12 Months, Gross Unrealized Losses	(689)	(754)
Greater than 12 Months, Fair Value	634	652
Greater Than 12 Months, Gross Unrealized Losses	(84)	(105)
Total, Fair Value	9,195	10,354
Total, Gross Unrealized Losses	(773)	(859)
Public corporate
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	2,511	2,455
Less Than 12 Months, Gross Unrealized Losses	(66)	(75)
Greater than 12 Months, Fair Value	129	113
Greater Than 12 Months, Gross Unrealized Losses	(6)	(6)
Total, Fair Value	2,640	2,568
Total, Gross Unrealized Losses	(72)	(81)
Private corporate
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	1,256	1,483
Less Than 12 Months, Gross Unrealized Losses	(37)	(38)
Greater than 12 Months, Fair Value	252	277
Greater Than 12 Months, Gross Unrealized Losses	(17)	(17)
Total, Fair Value	1,508	1,760
Total, Gross Unrealized Losses	(54)	(55)
U.S. Treasury, government and agency
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	4,626	5,356
Less Than 12 Months, Gross Unrealized Losses	(582)	(624)
Greater than 12 Months, Fair Value	0	0
Greater Than 12 Months, Gross Unrealized Losses	0	0
Total, Fair Value	4,626	5,356
Total, Gross Unrealized Losses	(582)	(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	18	18
Greater Than 12 Months, Gross Unrealized Losses	(2)	(2)
Total, Fair Value	18	18
Total, Gross Unrealized Losses	(2)	(2)
Foreign Govts
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	39	73
Less Than 12 Months, Gross Unrealized Losses	(2)	(3)
Greater than 12 Months, Fair Value	34	49
Greater Than 12 Months, Gross Unrealized Losses	(6)	(11)
Total, Fair Value	73	122
Total, Gross Unrealized Losses	(8)	(14)
Commercial Mortgage- backed
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	50	66
Less Than 12 Months, Gross Unrealized Losses	(1)	(5)
Greater than 12 Months, Fair Value	177	171
Greater Than 12 Months, Gross Unrealized Losses	(52)	(67)
Total, Fair Value	227	237
Total, Gross Unrealized Losses	(53)	(72)
Residential Mortgage- backed
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less Than 12 Months, Fair Value	29	47
Less Than 12 Months, Gross Unrealized Losses	0	0
Greater than 12 Months, Fair Value	4	4
Greater Than 12 Months, Gross Unrealized Losses	0	0
Total, Fair Value	33	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	47	218
Less Than 12 Months, Gross Unrealized Losses	(1)	(9)
Greater than 12 Months, Fair Value	12	12
Greater Than 12 Months, Gross Unrealized Losses	0	(1)
Total, Fair Value	59	230
Total, Gross Unrealized Losses	$ (1)	$ (10)