REVENUE RECOGNITION Revenue by Product by Region (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue from External Customer [Line Items]
Revenues	$ 5,920	$ 5,193
Opdivo [Member]
Revenue from External Customer [Line Items]
Revenues	1,801	1,511
Eliquis [Member]
Revenue from External Customer [Line Items]
Revenues	1,925	1,506
Orencia [Member]
Revenue from External Customer [Line Items]
Revenues	640	593
Sprycel [Member]
Revenue from External Customer [Line Items]
Revenues	459	438
Yervoy [Member]
Revenue from External Customer [Line Items]
Revenues	384	249
Empliciti [Member]
Revenue from External Customer [Line Items]
Revenues	83	55
Baraclude [Member]
Revenue from External Customer [Line Items]
Revenues	141	225
Mature Products And All Other [Member]
Revenue from External Customer [Line Items]
Revenues	487	616
UNITED STATES
Revenue from External Customer [Line Items]
Revenues	3,449	2,778
European Union [Member]
Revenue from External Customer [Line Items]
Revenues	1,480	1,406
Rest Of World [Member]
Revenue from External Customer [Line Items]
Revenues	874	873
Other Region [Member]
Revenue from External Customer [Line Items]
Revenues	$ 117	$ 136