BENEFITS PAYABLE - Schedule of Activity in Benefits Payable (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balances, beginning of period	$ 10,241	$ 9,264	$ 8,289
Acquisitions	0	62	0
Incurred related to:
Current year	101,365	89,266	76,105
Prior years	(701)	(872)	(415)
Total incurred	100,664	88,394	75,690
Paid related to:
Current year	(91,281)	(79,545)	(67,287)
Prior years	(9,184)	(7,934)	(7,428)
Total paid	(100,465)	(87,479)	(74,715)
Balances, end of period	$ 10,440	$ 10,241	$ 9,264