Segments (Revenue Reconciliation) (Details 2) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue
Revenue	$ 81,741	$ 92,793	$ 98,367
Total reportable segments
Revenue
Revenue	88,361	99,512	104,830
Other revenue
Revenue
Revenue	206	374	478
Elimination of internal transactions
Revenue
Revenue	$ (6,826)	$ (7,093)	$ (6,941)

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/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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