Commitments and Contingencies (Details) (Airline Capacity Purchase Arrangements [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2013
Airline Capacity Purchase Arrangements [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Aircraft Purchase Commitments, Due in Next Nine Months ending December 31, 2013	$ 865
Aircraft Purchase Commitments, Due in 2014	1,525
Aircraft Purchase Commitments, Due in 2015	815
Aircraft Purchase Commitments, Due in 2016	810
Aircraft Purchase Commitments, Due in 2017	760
Aircraft Purchase Commitments, Due after 2017	3,240
Aircraft Purchase Commitments, Total	$ 8,015

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the fifth fiscal year following the latest fiscal year.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 440

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6394976&loc=d3e25336-109308

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 47

-Paragraph 7

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the next fiscal year following the latest fiscal year.

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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the four fiscal year following the latest fiscal year.

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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the second fiscal year following the latest fiscal year.

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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the third fiscal year following the latest fiscal year.

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- Definition

Amount of the unrecorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

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Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing after the fifth fiscal year following the latest fiscal year.

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