Guarantees (Details) (USD $) In Millions	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2011
Guarantees (Textual) [Abstract]
Aircraft purchase from the lessor		$ 50
Leaseback agreement and the associated residual value guarantee charge		3
Realization of previously recognized loss on leaseback agreement and the associated residual value guarantee charge		22
Proceeds from sale of aircraft	26
Pre tax gain on sale of aircraft	$ 3

Cash received from sales of assets, other than those represented by other elements (securities, loans, mortgages, real estate).

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 27

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3536-108585

Name:	us-gaap_ProceedsFromSaleOfOtherAssets
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration