Energy & Transportation sales (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Energy and transportation sales
Energy &Transportation External Sales	$ 9,881	$ 12,758	$ 30,513	$ 40,656
Energy & Transportation
Energy and transportation sales
Energy &Transportation External Sales	3,475	4,562	10,634	13,319
Oil and Gas \| Energy & Transportation
Energy and transportation sales
Energy &Transportation External Sales	734	1,246	2,622	3,682
Power generation \| Energy & Transportation
Energy and transportation sales
Energy &Transportation External Sales	1,034	1,123	2,783	3,180
Industrial \| Energy & Transportation
Energy and transportation sales
Energy &Transportation External Sales	730	980	2,209	2,841
Transportation \| Energy & Transportation
Energy and transportation sales
Energy &Transportation External Sales	$ 977	$ 1,213	$ 3,020	$ 3,616

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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+ Details