Fair Value Measurements (Narrative) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value Measurements [Abstract]
Disposal of Long-Lived Assets	$ 82	$ 237
Long-Lived Assets fair value	38	107
Impairment charge of Long-Lived Assets	$ 44	$ 130

The carrying amount on the books of the entity of the asset to be abandoned.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 35

-Paragraph 47

-URI http://asc.fasb.org/extlink&oid=16397438&loc=d3e1794-110224

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 35

-Paragraph 48

-URI http://asc.fasb.org/extlink&oid=16397438&loc=d3e1816-110224

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 144

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_LongLivedAssetsToBeAbandonedCarryingValueOfAsset
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant