REVENUES - Equipment and Services Revenues (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Industrial Segment
Disaggregation of Revenue [Line Items]
Total Revenues	$ 28,657	$ 27,582	$ 56,052	$ 52,795
Industrial Segment | Equipment Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	13,245	13,776	26,058	26,628
Industrial Segment | Services Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	15,411	13,806	29,994	26,167
Power
Disaggregation of Revenue [Line Items]
Total Revenues	7,579	9,400	14,801	17,341
Power | Equipment Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	3,513	4,629	7,037	8,813
Power | Services Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	4,066	4,771	7,764	8,527
Renewable Energy
Disaggregation of Revenue [Line Items]
Total Revenues	1,653	2,312	3,299	4,079
Renewable Energy | Equipment Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	1,102	1,922	2,306	3,428
Renewable Energy | Services Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	551	390	993	651
Oil & Gas
Disaggregation of Revenue [Line Items]
Total Revenues	5,554	2,997	10,939	6,083
Oil & Gas | Equipment Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	2,189	1,273	4,417	2,564
Oil & Gas | Services Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	3,366	1,724	6,522	3,519
Aviation
Disaggregation of Revenue [Line Items]
Total Revenues	7,519	6,634	14,631	13,307
Aviation | Equipment Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	2,908	2,350	5,447	4,949
Aviation | Services Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	4,610	4,284	9,183	8,358
Healthcare
Disaggregation of Revenue [Line Items]
Total Revenues	4,978	4,688	9,680	8,993
Healthcare | Equipment Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	2,812	2,634	5,419	4,958
Healthcare | Services Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	2,166	2,054	4,261	4,035
Transportation
Disaggregation of Revenue [Line Items]
Total Revenues	942	1,077	1,814	2,057
Transportation | Equipment Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	305	510	571	1,009
Transportation | Services Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	637	567	1,243	1,048
Lighting
Disaggregation of Revenue [Line Items]
Total Revenues	431	473	887	935
Lighting | Equipment Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	416	457	860	908
Lighting | Services Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	$ 15	$ 16	$ 27	$ 29