ACQUISITIONS (Details) - USD ($) $ in Millions		1 Months Ended					12 Months Ended
ACQUISITIONS (Details) - USD ($) $ in Millions	Feb. 22, 2023	Oct. 31, 2025	Jul. 31, 2024	Mar. 31, 2024	Oct. 31, 2023	May 31, 2023	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Business Combination, Separately Recognized Transaction [Line Items]
Acquired in-process research and development expenses							$ 1,024	$ 4,663	$ 1,155
Stock-based compensation expense included in total costs and expenses							894	969	796
Research and development expenses
Business Combination, Separately Recognized Transaction [Line Items]
Stock-based compensation expense included in total costs and expenses							433	458	377
Selling, general and administrative expenses
Business Combination, Separately Recognized Transaction [Line Items]
Stock-based compensation expense included in total costs and expenses							401	450	361
Interius BioTherapeutics
Business Combination, Separately Recognized Transaction [Line Items]
Asset acquisition consideration		$ 350
Acquired in-process research and development expenses		$ 311
CymaBay
Business Combination, Separately Recognized Transaction [Line Items]
Asset acquisition consideration				$ 3,900
Acquired in-process research and development expenses								3,800
Stock-based compensation expense included in total costs and expenses								133
Asset acquisition, assets acquired								333
Asset acquisition, liabilities assumed								228
Liability payments								209
CymaBay \| Janssen Pharmaceutica NV
Business Combination, Separately Recognized Transaction [Line Items]
Payment to extinguish a future royalty obligation			$ 320
CymaBay \| Research and development expenses
Business Combination, Separately Recognized Transaction [Line Items]
Stock-based compensation expense included in total costs and expenses								67
CymaBay \| Selling, general and administrative expenses
Business Combination, Separately Recognized Transaction [Line Items]
Stock-based compensation expense included in total costs and expenses								67
XinThera, Inc
Business Combination, Separately Recognized Transaction [Line Items]
Acquired in-process research and development expenses					$ 50				170
Cash consideration						$ 200
Maximum potential future milestone payments						$ 760
Tmunity Therapeutics
Business Combination, Separately Recognized Transaction [Line Items]
Acquired in-process research and development expenses									244
Cash consideration	$ 300
Tmunity Therapeutics \| Tmunity And University Of Pennsylvania
Business Combination, Separately Recognized Transaction [Line Items]
Acquired in-process research and development expenses								$ 47	$ 25
Maximum potential future milestone payments							$ 1,000