OPERATING SEGMENTS - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) segment country	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Total revenues	$ 122,092	$ 123,693	$ 117,386
Property, plant and equipment - net	53,874	50,518
United States
Segment Reporting Information [Line Items]
Total revenues	46,312	53,624	53,238
Property, plant and equipment - net	17,643	14,987	14,273
Non US
Segment Reporting Information [Line Items]
Total revenues	75,780	70,069	64,148
Property, plant and equipment - net	$ 36,231	35,531	39,822
Renewable Energy
Segment Reporting Information [Line Items]
Number of countries in which segment operates (more than) | country	40
Total revenues	$ 10,211	9,022	6,261
Oil & Gas
Segment Reporting Information [Line Items]
Number of countries in which segment operates (more than) | country	120
Number of business segments | segment	4
Total revenues	$ 16,584	$ 12,515	$ 16,063