Segment Information (Details) $ in Millions	3 Months Ended
Mar. 31, 2016 USD ($) segment	Mar. 31, 2015 USD ($)
Segment information
Revenues	$ 4,401	$ 4,451
Expenses	3,707	3,802
OPERATING INCOME	$ 694	649
Number of reportable segments (segments) \| segment	2
Operating segments
Segment information
Revenues	$ 4,093	4,194
Expenses	2,051	2,071
OPERATING INCOME	$ 2,042	$ 2,123
Margin percentage (percent)	50.00%	51.00%
Business
Segment information
Revenues	$ 2,604	$ 2,697
Expenses	1,427	1,463
OPERATING INCOME	$ 1,177	$ 1,234
Margin percentage (percent)	45.00%	46.00%
Business \| Operating expense \| Restatement adjustment
Segment information
Expenses		$ (21)
Consumer
Segment information
Revenues	$ 1,489	1,497
Expenses	624	608
OPERATING INCOME	$ 865	$ 889
Margin percentage (percent)	58.00%	59.00%
Consumer \| Operating expense \| Restatement adjustment
Segment information
Expenses		$ 19

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

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Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

+ References

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The net result for the period of deducting operating expenses from operating revenues.

+ References

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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).

+ References

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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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.

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