Segments - Schedule of Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Segment Reporting Information, Profit (Loss)
Operating revenue	$ 1,468	$ 12,536	$ 10,060	$ 23,008
Operating income (loss)	(4,815)	2,128	(5,225)	3,148
Interest expense (income), net	194	75	273	158
Depreciation and amortization	591	713	1,268	1,328
Restructuring charges	2,454	0	2,454	0
Total assets, end of period	72,261	62,518	72,261	62,518	$ 64,532
Capital expenditures	282	1,560	1,218	2,920
Operating Segments | Airline
Segment Reporting Information, Profit (Loss)
Operating revenue	1,176	12,496	9,768	22,920
Operating income (loss)	(4,701)	2,091	(5,140)	3,145
Interest expense (income), net	196	84	277	177
Depreciation and amortization	591	713	1,268	1,328
Restructuring charges	2,454		2,454
Total assets, end of period	70,707	60,685	70,707	60,685
Capital expenditures	281	1,552	1,206	2,902
Operating Segments | Refinery
Segment Reporting Information, Profit (Loss)
Operating revenue	513	1,501	1,697	2,785
Operating income (loss)	(114)	37	(85)	3
Interest expense (income), net	(2)	(9)	(4)	(19)
Depreciation and amortization	25	25	49	48
Restructuring charges	0		0
Total assets, end of period	1,554	1,833	1,554	1,833
Capital expenditures	1	8	12	18
Intersegment Sales/Other
Segment Reporting Information, Profit (Loss)
Operating income (loss)	0	0	0	0
Interest expense (income), net	0	0	0	0
Depreciation and amortization	(25)	(25)	(49)	(48)
Restructuring charges	0		0
Total assets, end of period	0	0	0	0
Capital expenditures	0	0	0	0
Intersegment Sales/Other | Sales to airline segment
Segment Reporting Information, Profit (Loss)
Operating revenue	(3)	(307)	(214)	(578)
Intersegment Sales/Other | Exchanged products
Segment Reporting Information, Profit (Loss)
Operating revenue	(65)	(1,078)	(895)	(1,811)
Intersegment Sales/Other | Sales of refined products
Segment Reporting Information, Profit (Loss)
Operating revenue	$ (153)	$ (76)	$ (296)	$ (308)