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Number of aircraft committed to purchase.

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Percentage of employees represented by labor organizations

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

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Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

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

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Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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Commitments and Contingencies - Additional Information (Detail)		3 Months Ended
	Feb. 17, 2017 Aircraft	Mar. 31, 2017 USD ($) Employee Aircraft
Commitments and Contingencies [Line Items]
Aggregate balance		$ 10,700,000,000
Aircraft Mortgage Debt
Commitments and Contingencies [Line Items]
Guarantor obligations, maximum exposure		166,000,000
Tax-exempt special facilities revenue bonds
Commitments and Contingencies [Line Items]
Guarantor obligations, maximum exposure		1,900,000,000
Operating leases obligations		1,400,000,000
Capital leases obligations		421,000,000
Floating Rate Debt
Commitments and Contingencies [Line Items]
Debt instrument principal amount		3,000,000,000
Fixed Rate Debt
Commitments and Contingencies [Line Items]
Debt instrument principal amount		83,000,000
Loans And Leases From Non U S Entities
Commitments and Contingencies [Line Items]
Aggregate balance		$ 3,000,000,000
Minimum \| Tax-exempt special facilities revenue bonds
Commitments and Contingencies [Line Items]
Debt instrument maturity year		2017
Maximum
Commitments and Contingencies [Line Items]
Debt instrument, remaining terms (years)		12 years
Maximum \| Tax-exempt special facilities revenue bonds
Commitments and Contingencies [Line Items]
Debt instrument maturity year		2038
Maximum \| Loans And Leases From Non U S Entities
Commitments and Contingencies [Line Items]
Debt instrument, remaining terms (years)		12 years
United Airlines, Inc.
Commitments and Contingencies [Line Items]
Number of employees \| Employee		88,400
Percentage of employees represented by various U.S. labor organizations		80.00%
United Airlines, Inc. \| EETC
Commitments and Contingencies [Line Items]
Remaining proceeds from issuance of debt to be received in future periods		$ 555,000,000
Debt instrument principal amount		$ 1,973,000,000
United Airlines, Inc. \| Capital Addition Purchase Commitments
Commitments and Contingencies [Line Items]
New aircraft, scheduled delivery date		2027
United Airlines, Inc. \| Capital Addition Purchase Commitments \| Boeing 737NG
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered through the remainder of 2017 \| Aircraft		4
Number of aircraft committed to purchase \| Aircraft		12
United Airlines, Inc. \| Capital Addition Purchase Commitments \| B 787-9
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered through the remainder of 2017 \| Aircraft		1
United Airlines, Inc. \| Capital Addition Purchase Commitments \| Boeing 777-300ER Aircraft
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered through the remainder of 2017 \| Aircraft		6
United Airlines, Inc. \| Capital Addition Purchase Commitments \| Embraer E175 Aircraft
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered through the remainder of 2017 \| Aircraft		24
United Airlines, Inc. \| Capital Addition Purchase Commitments \| A319 aircraft
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered through the remainder of 2017 \| Aircraft		5
Air Wisconsin \| Minimum \| CRJ 200
Commitments and Contingencies [Line Items]
Number of aircraft to operate \| Aircraft	50
Air Wisconsin \| Maximum \| CRJ 200
Commitments and Contingencies [Line Items]
Number of aircraft to operate \| Aircraft	65