Related Party Transactions (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Related Party Transactions [Abstract]
Sales to related parties	[1]	$ 754	$ 629	$ 62
Purchases from related parties	[2]	$ 610	$ 570	$ 509

[1] Sales to related parties consists primarily of sales of refined products to PFJ Southeast, an equity affiliate which owns and operates travel plazas primarily in the Southeast region of the United States.

[2] We obtain transportation services and purchase ethanol from certain of our equity affiliates, none of which is individually material.