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Commitments and Contingencies - Additional Information (Detail)	1 Months Ended		6 Months Ended
	Mar. 31, 2016 Contract	Jan. 31, 2016	Jun. 30, 2016 USD ($) Employee Aircraft Contract
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			342,000,000
Aircraft Mortgage Debt
Commitments and Contingencies [Line Items]
Guarantor obligations, maximum exposure			43,000,000
Guarantor obligations, maximum additional exposure			129,000,000
Floating Rate Debt
Commitments and Contingencies [Line Items]
Debt instrument principal amount			2,400,000,000
Fixed Rate Debt
Commitments and Contingencies [Line Items]
Debt instrument principal amount			104,000,000
Loans And Leases From Non U S Entities
Commitments and Contingencies [Line Items]
Debt instrument principal amount			$ 2,400,000,000
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
Air Line Pilots Association International
Commitments and Contingencies [Line Items]
Service contract extended year		Jan. 31, 2019
Professional Airline Flight Control Association
Commitments and Contingencies [Line Items]
Service contract extended year	2021
Int'1 Association of Machinists
Commitments and Contingencies [Line Items]
Service contract extended year	2021		2021
Number of new contracts extended \| Contract	7		7
United Airlines, Inc.
Commitments and Contingencies [Line Items]
Number of employees \| Employee			87,500
Percentage of employees represented by various U.S. labor organizations			80.00%
Capital Addition Purchase Commitments \| United Airlines, Inc.
Commitments and Contingencies [Line Items]
New aircraft, scheduled delivery date			2024
Capital Addition Purchase Commitments \| United Airlines, Inc. \| Boeing 737NG
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered in the remainder of 2016 \| Aircraft			11
Capital Addition Purchase Commitments \| United Airlines, Inc. \| Boeing 777-300ER Aircraft
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered in the remainder of 2016 \| Aircraft			1
Capital Addition Purchase Commitments \| United Airlines, Inc. \| Embraer E175 Aircraft
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered in the remainder of 2016 \| Aircraft			5
Number of aircraft expected to be assigned immediately prior to each aircraft's delivery \| Aircraft			5