Retirement Benefits (Narrative) (Details) (USD $)	0 Months Ended	3 Months Ended
Apr. 13, 2012	Jan. 13, 2012	Mar. 31, 2012
Retirement Benefits [Abstract]
Contribution estimates on defined benefit pension plans		$ 6,500,000
Employer contributions to defined benefit pension plans	86,000,000
Principal terms of new business plan, cost savings			2,000,000,000
Principal terms of a new business plan, revenue enhancement			$ 1,000,000,000
Principal terms of new business, headcount reduced			13,000

The increase in the fair value of plan assets from contributions made by the employer.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

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