Segments - Schedule of Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Operating revenue	$ 11,107	$ 11,178	$ 31,202	$ 30,715
Operating income	2,213	835	6,085	3,034
Interest expense, net	121	154	379	513
Depreciation and amortization	466	440	1,384	1,333
Assets	53,646	51,940	53,646	51,940	$ 54,121
Capital expenditures	562	457	2,067	1,589
Airline
Segment Reporting Information [Line Items]
Operating revenue	10,994	11,114	30,900	30,651
Operating income	2,107	816	5,803	3,043
Interest expense, net	121	154	379	513
Depreciation and amortization	458	433	1,361	1,315
Assets	52,388	50,648	52,388	50,648
Capital expenditures	536	449	2,021	1,552
Refinery
Segment Reporting Information [Line Items]
Operating revenue	1,258	1,836	3,755	5,317
Operating income	106	19	282	(9)
Interest expense, net	0	0	0	0
Depreciation and amortization	8	7	23	18
Assets	1,258	1,292	1,258	1,292
Capital expenditures	26	8	46	37
Sales to airline segment | Intersegment Sales/Other
Segment Reporting Information [Line Items]
Operating revenue	(267)	(345)	(792)	(981)
Exchanged products | Intersegment Sales/Other
Segment Reporting Information [Line Items]
Operating revenue	(761)	(1,393)	(2,401)	(3,920)
Sales of refined products to third parties | Intersegment Sales/Other
Segment Reporting Information [Line Items]
Operating revenue	$ (117)	$ (34)	$ (260)	$ (352)