INTANGIBLE ASSETS - Summary of Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Gross  Carrying Amount	$ 31,894	$ 25,794
Accumulated Amortization	(10,667)	(10,121)
Foreign Currency Translation Adjustment	1	1
Net Carrying Amount	21,228	15,674
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross  Carrying Amount	39,014	39,014
Accumulated Amortization	(10,667)	(10,121)
Foreign Currency Translation Adjustment	1	1
Net Carrying Amount	28,348	28,894
IPR&D
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Gross  Carrying Amount	7,120	13,220
Foreign Currency Translation Adjustment	0	0
Net Carrying Amount	7,120	13,220
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Reclassified intangible assets	(6,100)
Intangible asset – sofosbuvir
Finite-Lived Intangible Assets [Line Items]
Gross  Carrying Amount	10,720	10,720
Accumulated Amortization	(6,525)	(6,350)
Foreign Currency Translation Adjustment	0	0
Net Carrying Amount	4,195	4,370
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	(6,525)	(6,350)
Intangible asset – axicabtagene ciloleucel
Finite-Lived Intangible Assets [Line Items]
Gross  Carrying Amount	7,110	7,110
Accumulated Amortization	(2,009)	(1,908)
Foreign Currency Translation Adjustment	0	0
Net Carrying Amount	5,101	5,202
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	(2,009)	(1,908)
Intangible asset – Trodelvy
Finite-Lived Intangible Assets [Line Items]
Gross  Carrying Amount	11,730	5,630
Accumulated Amortization	(1,192)	(973)
Foreign Currency Translation Adjustment	0	0
Net Carrying Amount	10,538	4,657
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	(1,192)	(973)
Reclassified intangible assets	6,100
Intangible asset – Hepcludex
Finite-Lived Intangible Assets [Line Items]
Gross  Carrying Amount	845	845
Accumulated Amortization	(179)	(158)
Foreign Currency Translation Adjustment	0	0
Net Carrying Amount	666	687
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	(179)	(158)
Other
Finite-Lived Intangible Assets [Line Items]
Gross  Carrying Amount	1,489	1,489
Accumulated Amortization	(762)	(733)
Foreign Currency Translation Adjustment	1	1
Net Carrying Amount	728	758
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	$ (762)	$ (733)