INTANGIBLE ASSETS - Summary of Intangible Assets, Net (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 31,884	$ 31,879
Accumulated Amortization	(15,421)	(14,822)
Foreign Currency Translation Adjustment	1	1
Foreign Currency Translation Adjustment	16,465	17,058
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Gross Carrying Amount	2,890	2,890
Foreign Currency Translation Adjustment	0	0
Net Carrying Amount	2,890	2,890
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	34,774	34,769
Accumulated Amortization	(15,421)	(14,822)
Foreign Currency Translation Adjustment	1	1
Net Carrying Amount	19,355	19,948
In Process Research And Development NSCLC
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Gross Carrying Amount	1,800
In Process Research And Development Bulevirtide
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Gross Carrying Amount	1,100
Intangible asset – sofosbuvir
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	10,720	10,720
Accumulated Amortization	(7,923)	(7,749)
Foreign Currency Translation Adjustment	0	0
Foreign Currency Translation Adjustment	2,797	2,971
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	(7,923)	(7,749)
Intangible asset – axicabtagene ciloleucel
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	7,110	7,110
Accumulated Amortization	(2,822)	(2,721)
Foreign Currency Translation Adjustment	0	0
Foreign Currency Translation Adjustment	4,288	4,389
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	(2,822)	(2,721)
Intangible asset – Trodelvy
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	11,730	11,730
Accumulated Amortization	(3,353)	(3,083)
Foreign Currency Translation Adjustment	0	0
Foreign Currency Translation Adjustment	8,377	8,647
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	(3,353)	(3,083)
Intangible asset – Hepcludex
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	845	845
Accumulated Amortization	(351)	(329)
Foreign Currency Translation Adjustment	0	0
Foreign Currency Translation Adjustment	494	516
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	(351)	(329)
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,479	1,474
Accumulated Amortization	(971)	(940)
Foreign Currency Translation Adjustment	1	1
Foreign Currency Translation Adjustment	510	535
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	$ (971)	$ (940)

Finite-Lived And Indefinite-Lived Intangible Assets, Foreign Currency Translation Gain (Loss), Cumulative Gain (Loss)

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