Stock-Based Compensation Stock-Based Compensation (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense		$ 17	$ 13	$ 61	$ 21
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	[1]	0	1	0	(14)
Other Deferred Compensation Arrangements, Liability, Current and Noncurrent		0		0		$ 6
Employee Service Share-based Compensation, Cash Flow Effect, Cash Used to Settle Awards				$ 4	$ 21
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Exercised				0.1	0.3
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	[2]	3	3	$ 11	$ 7
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				0.1
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 118.09
Market Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	[3]	8	7	$ 22	21
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				0.4
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 107.43
Other stock-based awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	[4]	6	$ 2	$ 28	$ 7
Western Refining Acquisition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense		$ 4		$ 21

[1] We had $6 million recorded in other current liabilities associated with our stock appreciation rights (“SARs”) awards at December 31, 2016. There were no SARs outstanding at September 30, 2017. We paid cash of $4 million to settle 0.1 million SARs that were exercised during the nine months ended September 30, 2017 and $21 million to settle 0.3 million SARs that were exercised during the nine months ended September 30, 2016.

[2] We granted 0.1 million market condition performance share awards at a weighted average grant date fair value of $118.09 per share under the 2011 Plan during the nine months ended September 30, 2017.

[3] We granted 0.4 million market stock units at a weighted average grant date fair value of $107.43 per unit under the amended and restated 2011 Long-Term Incentive Plan (“2011 Plan”) during the nine months ended September 30, 2017.

[4] We have aggregated expense for certain award types as they are not considered significant, including awards issued by Andeavor Logistics. During the three and nine months ended September 30, 2017, we recognized expense of $4 million and $21 million primarily related to pre-existing Western Refining, NTI and WNRL awards due to accelerated recognition required upon change-in-control on June 1, 2017. These Western Refining and NTI awards were converted to Andeavor shares on June 1, 2017. WNRL awards were converted to Andeavor Logistics units on the effective merger date of October 30, 2017. See Note 2.