BENEFITS PAYABLE - Activity in Benefits Payable (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balances, beginning of period	$ 9,264	$ 8,289	$ 8,143
Acquisitions	62	0	42
Incurred related to:
Current year	89,266	76,105	70,024
Prior years	(872)	(415)	(825)
Total incurred	88,394	75,690	69,199
Paid related to:
Current year	(79,545)	(67,287)	(62,149)
Prior years	(7,934)	(7,428)	(6,946)
Total paid	(87,479)	(74,715)	(69,095)
Balances, end of period	$ 10,241	$ 9,264	$ 8,289

The amount needed to reflect the estimated ultimate cost of settling claims relating to insured events that have occurred on or before the balance sheet date, whether or not reported to the insurer at that date.

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Amount of increase (decrease) in the cost of settling unpaid claims after deduction of reinsurance recoveries related to the acquisition of a business. Includes, but is not limited to, claims which have been incurred but not reported.

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Amount, after effects of reinsurance, of payments to settle claims incurred in the current period and related claims settlement costs.

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Amount, after effects of reinsurance, of payments to settle claims incurred in prior periods and related claims settlement costs.

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Amount, after effects of reinsurance, of expense (reversal of expense) for claims incurred and costs incurred in the claim settlement process.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount, after effects of reinsurance, of payments to settle insured claims and pay costs incurred in the claims settlement process.

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Amount, after effects of reinsurance, of expense (reversal of expense) for claims incurred in prior reporting periods and related claims settlement costs.

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