RESTRUCTURING NARRATIVE (Details) $ in Millions				12 Months Ended
	Jan. 01, 2019 USD ($)	Jan. 01, 2018 USD ($)	Jan. 01, 2017 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Restructuring Cost and Reserve [Line Items]
Provision for restructuring				$ 301	$ 131	$ 293
Celgene Integration [Member]
Restructuring Cost and Reserve [Line Items]
Cash outlays				$ 2,500
Workforce reduction of manufacturing, selling, administrative, and research and development personnel				125
Provision for restructuring				$ 256
Restructuring Related Costs, Asset Impairments				3
Total charges				674
Restructuring Reserve [Roll Forward]
Restructuring Reserve	$ 0			0
Payments for Restructuring				(34)
Restructuring Reserve				77	$ 0
Celgene Integration [Member] | Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring and related charges				2,800
Celgene Integration [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring and related charges				3,000
Celgene Integration [Member] | Research and development [Member]
Restructuring Cost and Reserve [Line Items]
Total charges				3
Celgene Integration [Member] | Other (income)/expense [Member]
Restructuring Cost and Reserve [Line Items]
Total charges				671
Operating Model 2020 [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Translation and Other Adjustment	(3)	$ 0	$ 0
Restructuring and related charges incurred to date				$ 1,400
Workforce reduction of manufacturing, selling, administrative, and research and development personnel				100	900	1,900
Employee termination costs				$ 17	$ 87	$ 267
Other Restructuring Costs				28	44	26
Provision for restructuring				45	131	293
Restructuring and Related Cost, Accelerated Depreciation				133	113	289
Restructuring Related Costs, Asset Impairments				127	16	241
Other shutdown costs				0	8	3
Total charges				305	268	826
Restructuring Reserve [Roll Forward]
Restructuring Reserve	99	186	114	99	186	114
Restructuring Reserve, Accrual Adjustment				(4)	(17)	(26)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)				(1)	1	18
Payments for Restructuring				(117)	(219)	(239)
Restructuring Reserve	$ 96	$ 186	$ 114	23	99	186
Operating Model 2020 [Member] | Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring and related charges				$ 1,500
Cash outlays percentage				40.00%
Operating Model 2020 [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring and related charges				$ 2,000
Cash outlays percentage				50.00%
Operating Model 2020 [Member] | Cost of products sold [Member]
Restructuring Cost and Reserve [Line Items]
Total charges				$ 180	57	149
Operating Model 2020 [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Total charges				1	1	1
Operating Model 2020 [Member] | Research and development [Member]
Restructuring Cost and Reserve [Line Items]
Total charges				79	79	383
Operating Model 2020 [Member] | Other (income)/expense [Member]
Restructuring Cost and Reserve [Line Items]
Total charges				$ 45	$ 131	$ 293