Acquisitions and Dispositions (Restructuring Charges - Narrative) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Nov. 01, 2010
Business Combinations [Abstract]
Deferred tax asset valuation allowance associated with branch restructuring	$ 0	$ 25
Liability recognized in purchase accounting for the anticipated and estimated costs associated with restructuring foreign branches into subsidiaries	$ 42		$ 277

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319

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