INVESTMENTS (FIXED MATURITIES AVAILABLE FOR SALE) (Details) $ in Millions	Dec. 31, 2017 USD ($) security	Dec. 31, 2016 USD ($) security
Investments, Debt and Equity Securities [Abstract]
Number of positions in unrealized loss position | security	620	794
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	$ 4,315	$ 9,702
Less than 12 Months, Gross unrealized Losses	23	754
12 Months or Longer, Fair Value	4,255	652
12 Months or Longer, Gross unrealized Losses	224	105
Total Fair Value	8,570	10,354
Total Gross unrealized losses	$ 247	859
Investments In Fixed Maturity Securities Other Disclosure [Abstract]
Debt securities exposure in single issuer greater than stated percentage of total investments	0.80%
Amortized Cost	$ 34,988	32,236
Trading securities, at fair value	12,628	9,134
Separate account equity investment carrying value	49	63
Public corporate
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	1,384	2,455
Less than 12 Months, Gross unrealized Losses	9	75
12 Months or Longer, Fair Value	548	113
12 Months or Longer, Gross unrealized Losses	16	6
Total Fair Value	1,932	2,568
Total Gross unrealized losses	25	81
Investments In Fixed Maturity Securities Other Disclosure [Abstract]
Exposure in single issuer of total investments	182	169
Amortized Cost	13,645	12,418
Private corporate
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	718	1,483
Less than 12 Months, Gross unrealized Losses	8	38
12 Months or Longer, Fair Value	615	277
12 Months or Longer, Gross unrealized Losses	23	17
Total Fair Value	1,333	1,760
Total Gross unrealized losses	31	55
Investments In Fixed Maturity Securities Other Disclosure [Abstract]
Amortized Cost	6,951	6,880
U.S. Treasury, government and agency
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	2,150	5,356
Less than 12 Months, Gross unrealized Losses	6	624
12 Months or Longer, Fair Value	3,005	0
12 Months or Longer, Gross unrealized Losses	179	0
Total Fair Value	5,155	5,356
Total Gross unrealized losses	185	624
Investments In Fixed Maturity Securities Other Disclosure [Abstract]
Amortized Cost	12,644	10,739
States and political subdivisions
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	20	0
Less than 12 Months, Gross unrealized Losses	0	0
12 Months or Longer, Fair Value	0	18
12 Months or Longer, Gross unrealized Losses	0	2
Total Fair Value	20	18
Total Gross unrealized losses	0	2
Investments In Fixed Maturity Securities Other Disclosure [Abstract]
Amortized Cost	414	432
Foreign governments
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	11	73
Less than 12 Months, Gross unrealized Losses	0	3
12 Months or Longer, Fair Value	73	49
12 Months or Longer, Gross unrealized Losses	5	11
Total Fair Value	84	122
Total Gross unrealized losses	5	14
Investments In Fixed Maturity Securities Other Disclosure [Abstract]
Amortized Cost	387	375
Commercial mortgage-backed
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	0	66
Less than 12 Months, Gross unrealized Losses	0	5
12 Months or Longer, Fair Value	0	171
12 Months or Longer, Gross unrealized Losses	0	67
Total Fair Value	0	237
Total Gross unrealized losses	0	72
Investments In Fixed Maturity Securities Other Disclosure [Abstract]
Amortized Cost	0	415
Residential mortgage-backed
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	18	47
Less than 12 Months, Gross unrealized Losses	0	0
12 Months or Longer, Fair Value	0	4
12 Months or Longer, Gross unrealized Losses	0	0
Total Fair Value	18	51
Total Gross unrealized losses	0	0
Investments In Fixed Maturity Securities Other Disclosure [Abstract]
Amortized Cost	236	294
Asset-backed
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	7	4
Less than 12 Months, Gross unrealized Losses	0	0
12 Months or Longer, Fair Value	2	8
12 Months or Longer, Gross unrealized Losses	0	1
Total Fair Value	9	12
Total Gross unrealized losses	0	1
Investments In Fixed Maturity Securities Other Disclosure [Abstract]
Amortized Cost	93	51
Redeemable preferred stock
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	7	218
Less than 12 Months, Gross unrealized Losses	0	9
12 Months or Longer, Fair Value	12	12
12 Months or Longer, Gross unrealized Losses	1	1
Total Fair Value	19	230
Total Gross unrealized losses	1	10
Investments In Fixed Maturity Securities Other Disclosure [Abstract]
Amortized Cost	461	519
Fixed maturities
Investments In Fixed Maturity Securities Other Disclosure [Abstract]
Amortized Cost	34,831	32,123
Unrealized loss on available for sale securities	1,527	447
Carrying value of fixed maturities non-income producing	3
Fixed maturities | Other Than Investment Grade | External Credit Rating, Non Investment Grade
Investments In Fixed Maturity Securities Other Disclosure [Abstract]
Available-for-sale securities, amortized cost basis other than investment grade	$ 1,309	$ 1,574
Percentage of available for sale securities	3.80%	4.90%
Unrealized loss on available for sale securities	$ 5	$ 28