INVESTMENTS - Fixed Maturities Available-for-sale (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	$ 5,718	$ 7,553
Less than 12 Months, Gross unrealized Losses	139	351
12 Months or Longer, Fair Value	485	672
12 Months or Longer, Gross unrealized Losses	59	32
Total Fair Value	6,203	8,225
Total Gross unrealized losses	198	383
Corporate
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	4,247	2,773
Less than 12 Months, Gross unrealized Losses	121	42
12 Months or Longer, Fair Value	369	373
12 Months or Longer, Gross unrealized Losses	50	20
Total Fair Value	4,616	3,146
Total Gross unrealized losses	171	62
U.S. Treasury, government and agency
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value		4,309
Less than 12 Months, Gross unrealized Losses		305
12 Months or Longer, Fair Value		2
12 Months or Longer, Gross unrealized Losses		0
Total Fair Value		4,311
Total Gross unrealized losses		305
States and political subdivisions
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value		112
Less than 12 Months, Gross unrealized Losses		3
12 Months or Longer, Fair Value		0
12 Months or Longer, Gross unrealized Losses		0
Total Fair Value		112
Total Gross unrealized losses		3
Foreign governments
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	88	11
Less than 12 Months, Gross unrealized Losses	1	0
12 Months or Longer, Fair Value	31	47
12 Months or Longer, Gross unrealized Losses	5	5
Total Fair Value	119	58
Total Gross unrealized losses	6	5
Asset-backed
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	1,324	319
Less than 12 Months, Gross unrealized Losses	16	1
12 Months or Longer, Fair Value	74	201
12 Months or Longer, Gross unrealized Losses	2	2
Total Fair Value	1,398	520
Total Gross unrealized losses	18	3
Redeemable preferred stock
Available For Sale Securities Continuous Unrealized Loss Position [Line Items]
Less than Twelve Months, Fair Value	59	29
Less than 12 Months, Gross unrealized Losses	1	0
12 Months or Longer, Fair Value	11	49
12 Months or Longer, Gross unrealized Losses	2	5
Total Fair Value	70	78
Total Gross unrealized losses	$ 3	$ 5