Equity Company Information (Schedule Of The Corporation's Percentage Ownership Interest) (Details)	Dec. 31, 2017
Upstream [Member] | Aera Energy LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	48.00%
Upstream [Member] | Barzan Gas Company Limited [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	7.00%
Upstream [Member] | BEB Erdgas und Erdoel GmbH & Co. KG [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Upstream [Member] | Cameroon Oil Transportation Company S.A. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	41.00%
Upstream [Member] | Cross Timbers Energy, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Upstream [Member] | Golden Pass LNG Terminal LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	18.00%
Upstream [Member] | Marine Well Containment Company LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	10.00%
Upstream [Member] | Mozambique Rovuma Venture, S.p.A. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	36.00%
Upstream [Member] | Nederlandse Aardolie Maatschappij B.V. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Upstream [Member] | Qatar Liquefied Gas Company Limited (2) [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	24.00%
Upstream [Member] | Ras Laffan Liquefied Natural Gas Company Limited [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	25.00%
Upstream [Member] | Ras Laffan Liquefied Natural Gas Company Limited (II) [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	31.00%
Upstream [Member] | Ras Laffan Liquefied Natural Gas Company Limited (3) [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	30.00%
Upstream [Member] | South Hook LNG Terminal Company Limited [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	24.00%
Upstream [Member] | Tengizchevroil, LLP [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	25.00%
Upstream [Member] | Terminale GNL Adriatico S.r.l. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	71.00%
Downstream [Member] | Fujian Refining & Petrochemical Co. Ltd. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	25.00%
Downstream [Member] | Permian Express Partners LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	12.00%
Downstream [Member] | Saudi Aramco Mobil Refinery Company Ltd. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Chemical [Member] | Al-Jubail Petrochemical Company [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Chemical [Member] | Infineum Italia s.r.l. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Chemical [Member] | Infineum Singapore Pte. Ltd. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Chemical [Member] | Infineum USA L.P. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%
Chemical [Member] | Saudi Yanbu Petrochemical Co. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership interest	50.00%