Restructuring and Other Items (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restructuring Cost and Reserve [Line Items]
Restructuring and other items	$ 402	$ 452	$ 242
Facilities, fleet and other [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other items	402	293	135
Severance and related costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other items	0	237	100
Routes and slots [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other items	$ 0	$ (78)	$ 7

The aggregate amount provided for estimated restructuring charges, remediation costs, and asset impairment loss during an accounting period. Generally, these items are either unusual or infrequent, but not both (in which case they would be extraordinary items).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.3)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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