Segment Information (Details) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) segment	Sep. 30, 2015 USD ($)
Segment information
Number of reportable segments (segments) \| segment			2
Revenues	$ 4,382	$ 4,554	$ 13,181	$ 13,424
Expenses	3,787	3,898	11,242	11,570
Total segment income	595	656	1,939	1,854
Operating segments
Segment information
Revenues	4,078	4,145	12,262	12,500
Expenses	2,200	2,165	6,392	6,376
Total segment income	$ 1,878	$ 1,980	$ 5,870	$ 6,124
Margin percentage (percent)	46.00%	48.00%	48.00%	49.00%
Business
Segment information
Revenues	$ 2,606	$ 2,636	$ 7,807	$ 7,991
Expenses	1,544	1,528	4,458	4,495
Total segment income	$ 1,062	$ 1,108	$ 3,349	$ 3,496
Margin percentage (percent)	41.00%	42.00%	43.00%	44.00%
Business \| Business \| Restatement adjustment
Segment information
Expenses		$ (13)		$ (55)
Consumer
Segment information
Revenues	$ 1,472	1,509	$ 4,455	4,509
Expenses	656	637	1,934	1,881
Total segment income	$ 816	$ 872	$ 2,521	$ 2,628
Margin percentage (percent)	55.00%	58.00%	57.00%	58.00%
Consumer \| Consumer \| Restatement adjustment
Segment information
Expenses		$ 15		$ 53

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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.

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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=63488584&loc=d3e20235-122688

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