ACQUISITIONS, DIVESTITURES, LICENSING AND OTHER ARRANGEMENTS - Schedule of Assets Acquired and Liabilities Assumed in Karuna Acquisition (Details) - Karuna - USD ($) $ in Millions		12 Months Ended
	Mar. 18, 2024	Dec. 31, 2024
Business Acquisition [Line Items]
Payments for asset acquisitions	$ 14,027
Transaction costs	55
Total consideration allocated	13,793
Cash and cash equivalents	1,167
Other assets	67
Intangible assets	100
Deferred income tax asset	542
Deferred income tax liability	(25)
Other liabilities	(180)
Total identifiable assets acquired, net	1,671
In Process Research and Development
Business Acquisition [Line Items]
Intangible assets	12,122
Common Stock
Business Acquisition [Line Items]
Payments for asset acquisitions	12,606
Equity
Business Acquisition [Line Items]
Payments for asset acquisitions	1,421
Unvested Equity Awards
Business Acquisition [Line Items]
Less: Charge for unvested stock awards	$ (289)
Unvested Equity Awards | Marketing, selling and administrative
Business Acquisition [Line Items]
Payments for asset acquisitions		$ 130
Unvested Equity Awards | Research and development
Business Acquisition [Line Items]
Payments for asset acquisitions		$ 159