Segments - Revenue Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue
Revenue	$ 73,620	$ 77,147	$ 79,591
Business Segments
Revenue
Revenue	79,758	82,274	84,235
Other
Revenue
Other - divested businesses	37	930	1,961
Other revenue	132	162	207
Internal transactions
Revenue
Revenue	$ (6,306)	$ (6,220)	$ (6,813)

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).

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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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+ Details