Income Taxes (Schedule of Income Tax Expense (Benefit) Intraperiod Tax Allocation) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Continuing Operations [Member]
Income Tax [Line Items]
Deferred income tax liability, net of current	$ 0	$ 1	$ 9
Other Comprehensive Income (Loss) [Member]
Income Tax [Line Items]
Deferred income tax liability, net of current	$ 0	$ (1)	$ (9)

The sum of income tax expense or benefit for the period that has been allocated among continuing operations, discontinued operations, extraordinary items, other comprehensive income, and items charged or credited directly to shareholders' equity.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 20

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=18498875&loc=d3e38679-109324

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