SEGMENTS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Segment Reporting Information, Profit (Loss)
Operating revenue	$ 16,673	$ 15,677	$ 47,361	$ 46,084
Airline salaries and related costs	4,443	4,231	12,928	12,035
Aircraft fuel and related costs	2,570	2,747	7,439	8,157
Depreciation and amortization	614	643	1,823	1,878
Operating Income	1,684	1,397	4,355	4,278
Interest expense/(income), net	171	173	521	567
Other non-operating expense (income)	(264)	(337)	(838)	255
Income/(loss) before income taxes	1,777	1,561	4,672	3,456
Total assets, end of period	79,623	75,368	79,623	75,368	$ 75,372
Capital expenditures	1,160	1,328	3,592	3,830
Operating Segments | Airline
Segment Reporting Information, Profit (Loss)
Operating revenue	15,197	14,594	43,681	42,564
Airline salaries and related costs	4,443	4,231	12,928	12,035
Aircraft fuel and related costs	2,570	2,747	7,439	8,157
Depreciation and amortization	614	643	1,823	1,878
Other segment items	5,939	5,543	17,178	16,292
Operating Income	1,631	1,430	4,313	4,202
Interest expense/(income), net	171	173	521	567
Other non-operating expense (income)	(264)	(337)	(838)	255
Income/(loss) before income taxes	1,724	1,594	4,630	3,380
Total assets, end of period	76,961	72,954	76,961	72,954
Capital expenditures	1,151	1,312	3,537	3,783
Operating Segments | Refinery
Segment Reporting Information, Profit (Loss)
Operating revenue	1,795	1,912	5,213	6,011
Refinery cost of goods sold	1,611	1,823	4,772	5,563
Depreciation and amortization	28	29	84	86
Other segment items	103	93	315	286
Operating Income	53	(33)	42	76
Interest expense/(income), net	1	(8)	3	3
Income/(loss) before income taxes	52	(25)	39	73
Total assets, end of period	2,680	2,490	2,680	2,490
Capital expenditures	9	16	55	47
Intersegment Sales/Other
Segment Reporting Information, Profit (Loss)
Operating revenue	(319)	(829)	(1,533)	(2,491)
Interest expense/(income), net	(1)	8	(3)	3
Income/(loss) before income taxes	1	(8)	3	3
Total assets, end of period	(18)	(76)	(18)	(76)
Intersegment Sales/Other | Sales to airline segment
Segment Reporting Information, Profit (Loss)
Operating revenue	(260)	(369)	(852)	(1,147)
Intersegment Sales/Other | Exchanged products
Segment Reporting Information, Profit (Loss)
Operating revenue	(23)	(349)	(549)	(1,147)
Intersegment Sales/Other | Sales of refined products
Segment Reporting Information, Profit (Loss)
Operating revenue	$ (36)	$ (111)	$ (132)	$ (197)