ASU 2014-09, Revenue - Revenue from Contracts with Customers (ASC 606) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cumulative effect of adopting new accounting standards			$ 68
Sales and other operating revenues, excluding consumer excise taxes	[1],[2]	$ 95,750
Cost of revenues	[2]	85,456	66,519	$ 56,676
Matching buy/sell receivables		1,640
Income taxes receivable		88
Accounting Standards Update 2014-09 [Member]
Cumulative effect of adopting new accounting standards			4
Accounting Standards Update 2014-09 [Member] | Sales and other operating revenues
Excise and sales taxes			5,150
Accounting Standards Update 2014-09 [Member] | Cost of revenues
Excise and sales taxes			$ 5,150
Accounting Standards Update 2014-09 [Member] | Consumer Excise Tax
Sales and other operating revenues, excluding consumer excise taxes		6,660
Cost of revenues		6,660
Accounting Standards Update 2014-09 [Member] | Third Party Reimbursements, Noncash Consideration and Imbalances
Sales and other operating revenues, excluding consumer excise taxes		502
Cost of revenues		$ 502

[1] The 2018 period reflects an election to present certain taxes on a net basis concurrent with our adoption of ASC 606.

[2] The 2018 period reflects an election to present certain taxes on a net basis concurrent with our adoption of ASU 2014-09, Revenue - Revenue from Contracts with Customers (“ASC 606”). See Notes 2 and 3 for further information.