INVESTMENTS - Fixed Maturities Available-for-sale (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Less than twelve months, fair value	$ 4,642	$ 2,196
Less than 12 months, gross unrealized losses	157	134
12 months or longer, fair value	38,852	44,061
12 months or longer, gross unrealized losses	7,339	6,836
Total fair value	43,494	46,257
Total gross unrealized losses	7,496	6,970
Corporate
Debt Securities, Available-for-sale [Line Items]
Less than twelve months, fair value	2,916	1,693
Less than 12 months, gross unrealized losses	141	119
12 months or longer, fair value	28,351	29,617
12 months or longer, gross unrealized losses	5,267	4,839
Total fair value	31,267	31,310
Total gross unrealized losses	5,408	4,958
U.S. Treasury, government and agency
Debt Securities, Available-for-sale [Line Items]
Less than twelve months, fair value	101	111
Less than 12 months, gross unrealized losses	3	2
12 months or longer, fair value	4,236	4,361
12 months or longer, gross unrealized losses	1,256	1,100
Total fair value	4,337	4,472
Total gross unrealized losses	1,259	1,102
States and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Less than twelve months, fair value	10	10
Less than 12 months, gross unrealized losses	0	0
12 months or longer, fair value	250	244
12 months or longer, gross unrealized losses	67	64
Total fair value	260	254
Total gross unrealized losses	67	64
Foreign governments
Debt Securities, Available-for-sale [Line Items]
Less than twelve months, fair value	31	8
Less than 12 months, gross unrealized losses	1	1
12 months or longer, fair value	483	514
12 months or longer, gross unrealized losses	120	109
Total fair value	514	522
Total gross unrealized losses	121	110
Residential mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Less than twelve months, fair value	182	74
Less than 12 months, gross unrealized losses	1	1
12 months or longer, fair value	986	1,030
12 months or longer, gross unrealized losses	137	127
Total fair value	1,168	1,104
Total gross unrealized losses	138	128
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Less than twelve months, fair value	1,355	238
Less than 12 months, gross unrealized losses	3	0
12 months or longer, fair value	1,716	5,499
12 months or longer, gross unrealized losses	78	107
Total fair value	3,071	5,737
Total gross unrealized losses	81	107
Commercial mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Less than twelve months, fair value	47	62
Less than 12 months, gross unrealized losses	8	11
12 months or longer, fair value	2,830	2,796
12 months or longer, gross unrealized losses	414	490
Total fair value	2,877	2,858
Total gross unrealized losses	$ 422	$ 501