Miscellaneous Financial Information (Government Assistance Narrative) (Details) - USD ($) $ in Billions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2022
Government Assistance [Line Items]
Government Assistance, Income, Increase (Decrease), Statement of Income or Comprehensive Income [Extensible Enumeration]	Crude oil and product purchases
Government Assistance, Affordable Fuel Pricing
Government Assistance [Line Items]
Government assistance, amount - before tax amount		$ 1.5

Amount of increase (decrease) in income from government assistance.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 832
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483507/832-10-50-3

+ Details

Name:	us-gaap_GovernmentAssistanceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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.

+ References

+ Details

Name:	us-gaap_GovernmentAssistanceLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Indicates line item in statement of income or comprehensive income that includes increase (decrease) in income from government assistance.

+ References

+ Details

Name:	us-gaap_GovernmentAssistanceStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration
Namespace Prefix:	us-gaap_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_GovernmentAssistanceTypeAxis=xom_GovernmentAssistanceAffordableFuelPricingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: