FAIR VALUE MEASUREMENTS AND FINANCIAL INSTRUMENTS - Acquisition-related Contingent Consideration Obligations, Reconciliation of Contingent Consideration Obligations (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation
Balance, beginning of period	$ 316	$ 339
Acquisition-related contingent consideration	26	2
Payments	(30)	(28)
Balance, end of period	312	313
Current portion included in Accrued and other current liabilities	37	46
Non-current portion	275	267
Accretion for the time value of money
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation
Acquisition-related contingent consideration	17	16
Fair value adjustments due to changes in estimates of other future payments
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation
Acquisition-related contingent consideration	$ 9	$ (14)

Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled within one year or the normal operating cycle, if longer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 35
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Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled beyond one year or the normal operating cycle, if longer.

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- Definition

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

+ References

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- Definition

Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
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- Definition

Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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- Definition

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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