REVENUE REVENUE BY PRODUCT AND REGION (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue from External Customer [Line Items]
Revenues	$ 5,973	$ 5,691	$ 5,704	$ 5,193	$ 5,449	$ 5,254	$ 5,144	$ 4,929	$ 22,561	$ 20,776	$ 19,427
Opdivo [Member]
Revenue from External Customer [Line Items]
Revenues									6,735	4,948	3,774
Eliquis [Member]
Revenue from External Customer [Line Items]
Revenues									6,438	4,872	3,343
Orencia [Member]
Revenue from External Customer [Line Items]
Revenues									2,710	2,479	2,265
Sprycel [Member]
Revenue from External Customer [Line Items]
Revenues									2,000	2,005	1,824
Yervoy [Member]
Revenue from External Customer [Line Items]
Revenues									1,330	1,244	1,053
Empliciti [Member]
Revenue from External Customer [Line Items]
Revenues									247	231	150
Baraclude [Member]
Revenue from External Customer [Line Items]
Revenues									744	1,052	1,192
Sustiva Franchise [Member]
Revenue from External Customer [Line Items]
Revenues									283	729	1,065
Reyataz [Member]
Revenue from External Customer [Line Items]
Revenues									427	698	912
Hepatitis C Portfolio [Member]
Revenue from External Customer [Line Items]
Revenues									17	406	1,578
Mature Products And All Other [Member]
Revenue from External Customer [Line Items]
Revenues									1,630	2,112	2,271
UNITED STATES
Revenue from External Customer [Line Items]
Revenues									12,586	11,358	10,720
European Union [Member]
Revenue from External Customer [Line Items]
Revenues									5,658	4,988	4,215
Rest Of World [Member]
Revenue from External Customer [Line Items]
Revenues									3,733	3,877	3,964
Other Region [Member]
Revenue from External Customer [Line Items]
Revenues									$ 584	$ 553	$ 528