DERIVATIVE FINANCIAL INSTRUMENTS - Summary of Classification and Fair Value of Derivative Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	$ 28	$ 12
Derivative liability, fair value	(30)	(121)
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	28	0
Derivative liability, fair value	(30)	(120)
Designated as Hedging Instrument \| Prepaid and other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	24	0
Designated as Hedging Instrument \| Other accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	(30)	(113)
Designated as Hedging Instrument \| Other long-term assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	4	0
Designated as Hedging Instrument \| Other long-term obligations
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	0	(7)
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	0	12
Derivative liability, fair value	0	(1)
Not Designated as Hedging Instrument \| Prepaid and other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	0	12
Not Designated as Hedging Instrument \| Other accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	$ 0	$ (1)

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and elected not to be offset.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313

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- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and elected not to be offset.

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- Definition

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+ References

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