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(Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
(Details) - USD ($) $ in Millions	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Related Party Transaction [Line Items]
Investment in unconsolidated affiliate	$ 136		$ 136		$ 121
Equity in earnings of unconsolidated affiliate	1	$ 0	2	$ 0
Advances from affiliates	138		138		140
Receivables from affiliates	6		6		12
Accounts payable to affiliates	$ 29		$ 29		$ 49
JCNolan [Member]
Related Party Transaction [Line Items]
Equity Method Investment, Ownership Percentage	50.00%		50.00%
Wholesale motor fuel sales to affiliates [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	$ 37	0	$ 49	1
Wholesale Motor Fuel [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Purchases from Related Party	$ 120	$ 103	$ 439	$ 282