Details of Pass Through Trusts (Detail) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014
Debt Instrument [Line Items]
Proceeds received from issuance of debt	$ 228	$ 395
EETC
Debt Instrument [Line Items]
Total debt recorded	1,061
Proceeds received from issuance of debt	917
Remaining proceeds from issuance of debt to be received in future periods	0
EETC \| August 2014
Debt Instrument [Line Items]
Principal	1,061
United Airlines, Inc.
Debt Instrument [Line Items]
Proceeds received from issuance of debt	228	$ 395
United Airlines, Inc. \| Class A Pass Through Certificates \| August 2014
Debt Instrument [Line Items]
Principal	$ 823
Final expected distribution date	2026-09
Stated interest rate	3.75%
Total debt recorded	$ 823
Proceeds received from issuance of debt	711
Remaining proceeds from issuance of debt to be received in future periods	0
United Airlines, Inc. \| Class B Pass Through Certificates \| August 2014
Debt Instrument [Line Items]
Principal	$ 238
Final expected distribution date	2022-09
Stated interest rate	4.625%
Total debt recorded	$ 238
Proceeds received from issuance of debt	206
Remaining proceeds from issuance of debt to be received in future periods	$ 0

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Amount of borrowing capacity currently available under the debt instrument (initial borrowing capacity less the amount of proceeds received).

+ References

No definition available.

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Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

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-Paragraph 1

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Face (par) amount of debt instrument at time of issuance.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

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

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-Name Accounting Standards Codification

-Topic 230

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-URI http://asc.fasb.org/extlink&oid=6513228

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