Income Taxes (Unrecognized Tax Benefits Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Examination, Penalties and Interest Expense [Abstract]
Interest on tax deficiencies	$ (73)	$ 11	$ (20)
Income tax penalties	$ (47)	$ 6	$ 22

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