Income Taxes (Reconciliation of the beginning and ending amounts of unrecognized tax benefits) (Narratives) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Interest on tax deficiencies	$ (68)	$ 22	$ (45)
Income tax penalties	$ (45)		$ 33

The amount of estimated penalties recognized in the period arising from income tax examinations.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

Name:	us-gaap_IncomeTaxExaminationPenaltiesExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration