Discontinued Operations Schedule of operation result associated with discontinued operations (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Operating Income									$ 360	$ 724	$ 686
Revenues	$ 3,877	$ 4,761	$ 4,607	$ 3,749	$ 2,959	$ 3,064	$ 2,892	$ 2,808	16,994	11,723	9,986
Total cost of sales									15,872	10,615	8,830
General and administrative									141	140	155
Other operating										375	374
Rent									72	81	81
Loss on disposal of assets and impairment charges									19	114	225
Depreciation, amortization and accretion									182	203	319
Total cost of sales and operating expenses									16,649	11,494	9,841
Operating income									345	229	145
Interest expense, net									146	245	189
Loss on extinguishment of debt and other									(129)	0	0
Income tax expense (benefit)									34	(306)	(72)
Loss from discontinued operations, net of income taxes									(265)	(177)	(462)
Motor Fuels [Member]
Revenues									16,504	10,910	9,212
Discontinued Operations [Member]
Other Operating Income									93	1,827	1,789
Revenues									349	6,964	5,712
General and administrative									7	168	114
Other operating									57	707	685
Rent									4	56	59
Loss on disposal of assets and impairment charges									61	286	455
Depreciation, amortization and accretion									0	34	143
Total cost of sales and operating expenses									434	7,057	6,105
Operating income									(85)	(93)	(393)
Interest expense, net									2	36	28
Loss on extinguishment of debt and other									(20)	0	0
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax									(107)	(129)	(421)
Income tax expense (benefit)									158	48	41
Loss from discontinued operations, net of income taxes									(265)	(177)	(462)
Discontinued Operations [Member] | Merchandise [Member]
Other Operating Income									89	1,800	1,700
Discontinued Operations [Member] | Motor Fuels [Member]
Revenues									256	5,137	3,923
Total cost of sales									$ 305	$ 5,806	$ 4,649