ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Reclassifications (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Benefits and settlement expenses, net of reinsurance ceded	$ (1,093)	$ (1,127)	$ (2,398)	$ (2,478)
Tax (expense) benefit	(39)	(32)	(64)	(2)
Change in net expected credit losses - fixed maturities	0	(30)	5	(82)
Net income	162	142	264	13
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) | Gains and losses on derivative instruments
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Benefits and settlement expenses, net of reinsurance ceded	0	(1)	0	(3)
Tax (expense) benefit	0	0	0	1
Net income	0	(1)	0	(2)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) | Unrealized gains and losses on available-for-sale securities
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Tax (expense) benefit	(2)	6	(9)	8
Realized gains (losses) - investments	9	2	38	42
Change in net expected credit losses - fixed maturities	0	(30)	5	(82)
Net income	$ 7	$ (22)	$ 34	$ (32)