Aircraft Related Charges Gains Net

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Debt instrument maturity year

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- Definition

Goodwill Impairment Credit

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Labor agreement costs, Settled with Cash

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- Definition

Number Of Flight Attendants Offering To Retire Early

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Number of flight attendants voluntarily on leave

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Number of mechanics offering to retire early

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- Definition

Revenue recognition new accounting pronouncement.

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No definition available.

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- Definition

The effective interest rate on the liability component of convertible debt instrument which may be settled in cash upon conversion, including partial cash settlement.

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-Name Accounting Standards Codification

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The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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Interest rate stated in the contractual debt agreement.

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Gross amount of debt extinguished.

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No definition available.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of an intangible asset (excluding goodwill) to fair value.

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The loss recognized on termination of a contract.

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Amount of payroll tax expense, compensation, postemployment and benefit-related expenses not elsewhere specified in the taxonomy (such as health plan, profit sharing, incentives, tuition reimbursement, other fringe benefits and perquisites) incurred in the period.

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Period expense related to postemployment benefits.

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Merger and Integration-Related Costs and Special Items - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012 AirCraft	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Merger, Acquisition, Integration Costs and Other Charges [Line Items]
Special revenue item							$ 107			$ 107
Debt extinguishment charge									309
Fair value of liabilities extinguished									212
Labor agreement costs	21	454							475
Expected cash payment									55
Severance and benefits			76	49					125
Number of mechanics offering to retire early				400
Number of flight attendants voluntarily on leave				1,800
Number of flight attendants accepted voluntary retirement			1,300
Intangible asset impairment	24			6	4				30	4	29
Aircraft-related charges (gains), net					(2)	(3)	1	(2)	46
Goodwill impairment credit											64
Termination of maintenance service contract					58					58		104
8% Notes Indenture
Merger, Acquisition, Integration Costs and Other Charges [Line Items]
Debt instrument stated interest rate					8.00%					8.00%
Debt instrument, fair value					88					88
Principal amount of senior notes					125					125
UAL 8% Contingent Senior Notes
Merger, Acquisition, Integration Costs and Other Charges [Line Items]
Debt instrument stated interest rate					8.00%					8.00%
Principal amount of senior notes	188				125				188	125
Debt instrument convertible effective interest rate									8.00%	8.00%
United Air Lines 8% Senior Notes Due 2024
Merger, Acquisition, Integration Costs and Other Charges [Line Items]
Principal amount of senior notes	400								400
Debt instrument maturity year	2024								2024
UAL 6% Senior Convertible Notes
Merger, Acquisition, Integration Costs and Other Charges [Line Items]
Principal amount of senior notes	652								652
Debt instrument convertible effective interest rate									6.00%	6.00%	6.00%
Debt instrument maturity year	2031								2031
Pilot Disability Plan
Merger, Acquisition, Integration Costs and Other Charges [Line Items]
Labor agreement costs									80
Voluntary retirement program
Merger, Acquisition, Integration Costs and Other Charges [Line Items]
Severance and benefits				32
Voluntary leave of absence program
Merger, Acquisition, Integration Costs and Other Charges [Line Items]
Severance and benefits				17
United Airlines, Inc.
Merger, Acquisition, Integration Costs and Other Charges [Line Items]
Special revenue item										107
Intangible asset impairment											$ 29
United Airlines, Inc. \| UAL 8% Contingent Senior Notes
Merger, Acquisition, Integration Costs and Other Charges [Line Items]
Debt instrument convertible effective interest rate									8.00%	8.00%
United Airlines, Inc. \| UAL 6% Senior Convertible Notes
Merger, Acquisition, Integration Costs and Other Charges [Line Items]
Debt instrument convertible effective interest rate									6.00%	6.00%	6.00%