Retirement Benefits (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Required contributions	$ 168
AA [Member]
Defined Benefit Plan Disclosure [Line Items]
Required contributions	168
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	613
Pension Plans [Member] \| AA [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 613

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 Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

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