REVENUE RECOGNITION - Other Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Operating revenue	$ 15,578	$ 13,824	$ 28,337	$ 23,173
Other
Disaggregation of Revenue [Line Items]
Operating revenue	2,201	2,594	4,340	4,747
Refinery
Disaggregation of Revenue [Line Items]
Operating revenue	965	1,514	1,882	2,700
Loyalty program
Disaggregation of Revenue [Line Items]
Operating revenue	774	650	1,500	1,221
Ancillary businesses
Disaggregation of Revenue [Line Items]
Operating revenue	214	206	445	416
Miscellaneous
Disaggregation of Revenue [Line Items]
Operating revenue	$ 248	$ 224	$ 513	$ 410