BENEFITS PAYABLE - Incurred and Paid Claims Development (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Claims Development [Line Items]
Incurred Claims, Net of Reinsurance	$ 234,259
Cumulative Paid Claims, Net of Reinsurance	224,018
Benefits payable, net of reinsurance	10,241
2021 and Prior Claims Incurred Year
Claims Development [Line Items]
Incurred Claims, Net of Reinsurance	69,484	$ 69,698	$ 70,066
Cumulative Paid Claims, Net of Reinsurance	69,484	69,252	$ 62,149
2022 Claims Incurred Year
Claims Development [Line Items]
Incurred Claims, Net of Reinsurance	75,447	76,105
Cumulative Paid Claims, Net of Reinsurance	74,989	$ 67,287
2023 Claims Incurred Year
Claims Development [Line Items]
Incurred Claims, Net of Reinsurance	89,328
Cumulative Paid Claims, Net of Reinsurance	$ 79,545