Segments - Schedule of Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Segment Reporting Information, Profit (Loss)
Operating revenue	$ 10,483	$ 11,107	$ 30,181	$ 31,202
Operating income (loss)	1,969	2,213	5,932	6,085
Interest expense, net	95	121	295	379
Depreciation and amortization	474	466	1,430	1,384
Assets	50,948	53,545	50,948	53,545	$ 53,134
Capital expenditures	680	562	2,597	2,067
Operating Segments | Airline
Segment Reporting Information, Profit (Loss)
Operating revenue	10,473	10,994	30,043	30,900
Operating income (loss)	2,014	2,107	6,015	5,803
Interest expense, net	94	121	293	379
Depreciation and amortization	464	458	1,402	1,361
Assets	49,748	52,287	49,748	52,287
Capital expenditures	652	536	2,536	2,021
Operating Segments | Refinery
Segment Reporting Information, Profit (Loss)
Operating revenue	971	1,258	2,763	3,755
Operating income (loss)	(45)	106	(83)	282
Interest expense, net	1	0	2	0
Depreciation and amortization	10	8	28	23
Assets	1,200	1,258	1,200	1,258
Capital expenditures	28	26	61	46
Intersegment Sales/Other | Sales to airline segment
Segment Reporting Information, Profit (Loss)
Operating revenue	(173)	(267)	(495)	(792)
Intersegment Sales/Other | Exchanged products
Segment Reporting Information, Profit (Loss)
Operating revenue	(734)	(761)	(2,005)	(2,401)
Intersegment Sales/Other | Sales of refined products to third parties
Segment Reporting Information, Profit (Loss)
Operating revenue	$ (54)	$ (117)	$ (125)	$ (260)