Contractual Principal Payments Under then-Outstanding Long Term Debt (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013
Debt Instrument [Line Items]
Last nine months of 2013	$ 859
2014	958
2015	2,044
2016	1,003
2017	566
After 2017	5,985
Long-term debt	11,415
United Airlines, Inc.
Debt Instrument [Line Items]
Last nine months of 2013	859
2014	958
2015	2,044
2016	1,003
2017	566
After 2017	5,640
Long-term debt	$ 11,070

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 210

-Section S99

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-Article 9

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

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-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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