BENEFITS PAYABLE - Schedule of Incurred and Paid Claims Development (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Claims Development [Line Items]
Incurred Claims, Net of Reinsurance	$ 300,852
Cumulative Paid Claims, Net of Reinsurance	290,885
Benefits payable, net of reinsurance	9,967
2023 & Prior
Claims Development [Line Items]
Incurred Claims, Net of Reinsurance	88,615	$ 88,675	$ 89,328
Cumulative Paid Claims, Net of Reinsurance	88,584	88,319	$ 79,545
2024
Claims Development [Line Items]
Incurred Claims, Net of Reinsurance	100,396	101,365
Cumulative Paid Claims, Net of Reinsurance	100,086	$ 91,281
2025
Claims Development [Line Items]
Incurred Claims, Net of Reinsurance	111,841
Cumulative Paid Claims, Net of Reinsurance	$ 102,215