FAIR VALUE - Narrative (Details) - USD ($)	6 Months Ended	12 Months Ended
Jun. 30, 2024	Dec. 31, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Swap liability	$ 20,000,000
Swap asset		$ 68,000,000
Securities lending invested collateral
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cumulative, aggregate adjustment	(20,000,000)
Put option
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of financial liability	800,000,000	595,000,000
Call option
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of financial asset	23,000,000	18,000,000
Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt	0	871,000,000
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt outstanding	12,900,000,000	10,800,000,000
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt outstanding	12,400,000,000	10,600,000,000
Unobservable Inputs (Level 3) \| Recurring Basis
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total invested assets	$ 256,000,000	$ 218,000,000
Investments \| Fair Value Risk \| Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Concentration risk (percent)	1.10%	1.00%

Financial Assets, Fair Value Disclosure

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Fair value portion of asset recognized for present right to economic benefit.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.

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Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk.

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Fair value as of the balance sheet date of all derivative assets designated as interest rate fair value hedging instruments.

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Fair value as of the balance sheet date of all derivative liabilities designated as interest rate fair value hedging instruments.

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Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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