FAIR VALUE MEASUREMENTS - Additional Information (Details) € in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Mar. 31, 2021 EUR (€)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying amount related to borrowings	$ 25,193		$ 24,987
In-process research and development impairment	2,430	$ 0
Liability related to assumed R&D financing arrangement | CymaBay
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying amount related to borrowings	199		0
Immunomedics | Fair Value, Nonrecurring | Level 3 | Estimate of Fair Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Future royalties	1,200		1,200
Immunomedics | Fair Value, Nonrecurring | Level 3 | Carrying value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Future royalties	$ 1,200		$ 1,200
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency derivative contract maturities (in months)	18 months
Maximum | MYR GmbH
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability for MYR GmbH (“MYR”) contingent consideration | €				€ 300