Financial Instruments and Derivatives - Derivative Instruments (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Realized and Unrealized Before-Tax Gain / Loss on Derivative Instruments Recognized in the Consolidated Statement of Income
Sales and other operating revenue	$ 178,574	$ 255,583	$ 279,332
Crude oil and product purchases	94,007	143,801	156,172
Not Designated As Hedging Instrument, Trading [Member]
Realized and Unrealized Before-Tax Gain / Loss on Derivative Instruments Recognized in the Consolidated Statement of Income
Sales and other operating revenue	404	(412)	130
Crude oil and product purchases	(407)	179	(120)
Total	$ (3)	$ (233)	$ 10

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.

No definition available.

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Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

+ References

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-Publisher FASB
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-Paragraph 4A
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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
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-Publisher FASB
-Name Accounting Standards Codification
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Purchase cost of crude oil, products and other raw materials, feedstocks, semi finished products, finished products and other merchandise that become part of salable products for oil and gas, refining and marketing and chemical operations.

+ References

No definition available.

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