Interim Financial Information	9 Months Ended
	Sep. 30, 2020
Interim Financial Information [Abstract]
Interim Financial Information	Interim Financial InformationThe unaudited interim financial information presented in the financial statements included in this report is prepared in accordance with generally accepted accounting principles in the United States (GAAP) and includes all known accruals and adjustments necessary, in the opinion of management, for a fair presentation of the consolidated financial position of Phillips 66 and its results of operations and cash flows for the periods presented. Unless otherwise specified, all such adjustments are of a normal and recurring nature. Certain notes and other information have been condensed or omitted from the interim financial statements included in this report. Therefore, these interim financial statements should be read in conjunction with the consolidated financial statements and notes included in our 2019 Annual Report on Form 10-K. The results of operations for the three and nine months ended September 30, 2020, are not necessarily indicative of the results expected for the full year.