Discontinued Operations Schedule of Operating Results Associated with Discontinued Operations (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues		$ 4,098	$ 4,331	$ 4,475	$ 3,692	$ 3,877	$ 4,761	$ 4,607	$ 3,749	$ 16,596	$ 16,994	$ 11,723
General and administrative										136	141	140
Other operating										304	363	375
Lease expense											72	81
Loss on disposal of assets and impairment charges										(68)	(19)	(114)
Depreciation, amortization and accretion										183	182	169
Operating income (loss)		$ 98	$ 117	$ 97	$ 152	$ (38)	$ 159	$ 128	$ 96	464	345	229
Interest expense, net										173	144	209
Loss on extinguishment of debt and other, net										0	109	0
Income tax expense (benefit)										(17)	34	(306)
Loss from discontinued operations, net of income taxes										0	(265)	(177)
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues											349	6,964
Cost of sales											305	5,806
General and administrative											7	168
Other operating											57	707
Lease expense											4	56
Loss on disposal of assets and impairment charges											(61)	(286)
Depreciation, amortization and accretion											0	34
Total cost of sales and operating expenses											434	7,057
Operating income (loss)											(85)	(93)
Interest expense, net											2	36
Loss on extinguishment of debt and other, net											(20)	0
Loss from discontinued operations before income taxes											(107)	(129)
Income tax expense (benefit)											158	48
Loss from discontinued operations, net of income taxes											(265)	(177)
Motor Fuel Sales [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues										16,176	16,504	10,910
Motor Fuel Sales [Member] | Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues											256	5,137
Non Motor Fuel Sales [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues										$ 278	360	724
Non Motor Fuel Sales [Member] | Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues	[1]										93	1,827
Merchandise [Member] | Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues											$ 89	$ 1,800

[1] Non motor fuel sales includes merchandise sales totaling $89 million and $1.8 billion for the years ended December 31, 2018 and 2017, respectively.