ACQUISITIONS, GOODWILL AND OTHER INTANGIBLE ASSETS - Intangible Assets Subject to Amortization (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 31,516	$ 30,618
Accumulated amortization	(13,105)	(12,561)
Net	18,412	18,056
Customer-related
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	10,844	10,614
Accumulated amortization	(3,319)	(3,095)
Net	7,528	7,521
Patents and technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	10,906	10,271
Accumulated amortization	(4,072)	(3,899)
Net	6,834	6,372
Capitalized software
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	8,083	8,064
Accumulated amortization	(5,054)	(4,974)
Net	3,029	3,089
Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,257	1,280
Accumulated amortization	(475)	(421)
Net	782	859
Lease valuations
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	161	170
Accumulated amortization	(83)	(80)
Net	79	89
All other
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	264	218
Accumulated amortization	(102)	(92)
Net	$ 162	$ 125