Related-Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Investment in unconsolidated affiliate	$ 121	$ 0
Equity in earnings of unconsolidated affiliate	2	0	$ 0
Sales Revenue From Wholesale Fuel Sales To Affiliates	7	33	55
Bulk Fuel Purchases From Affiliates	821	1,947	$ 2,416
Advances from affiliates	140	24
Receivables from affiliates	12	37
Accounts payable to affiliates	$ 49	$ 149
Philadelphia Energy Solutions [Member]
Related Party Transaction [Line Items]
Cost of sales attributable to related-party purchases (percent)		8.30%	19.60%

Fuel purchases from affiliates

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Revenue from the wholesale sale and distribution of motor fuel to affiliates.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount of receivables due from an entity that is affiliated with the reporting entity by means of direct or indirect ownership, due within 1 year (or 1 business cycle).

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Amount of payable due to an entity that is affiliated with the reporting entity by means of direct or indirect ownership. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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