Commitments and Contingencies - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies [Line Items]
Percentage of employees represented by various U.S. labor organizations	80.00%
Revolving Credit Facility
Commitments and Contingencies [Line Items]
Capacity available under the revolving credit facility	$ 1,000,000,000
Tax-exempt special facilities revenue bonds
Commitments and Contingencies [Line Items]
Guarantor obligations, maximum exposure	1,600,000,000
Operating leases obligations	1,300,000,000
Capital leases obligations	272,000,000
Floating Rate Debt
Commitments and Contingencies [Line Items]
Debt instrument principal amount	1,900,000,000
Fixed Rate Debt
Commitments and Contingencies [Line Items]
Debt instrument principal amount	246,000,000
Loans And Leases From Non U S Entities
Commitments and Contingencies [Line Items]
Debt instrument principal amount	$ 2,100,000,000
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
Minimum | Tax-exempt special facilities revenue bonds
Commitments and Contingencies [Line Items]
Debt instrument maturity year	2015
United Airlines, Inc.
Commitments and Contingencies [Line Items]
Number of employees	86,000
Capital Addition Purchase Commitments | Embraer 175 aircraft
Commitments and Contingencies [Line Items]
Number of aircraft without financing arrangement expected to be delivered	7
Capital Addition Purchase Commitments | United Airlines, Inc. | Boeing 737-900ER aircraft
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered	9
Capital Addition Purchase Commitments | United Airlines, Inc. | Boeing 787-8
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered	1
Capital Addition Purchase Commitments | United Airlines, Inc. | Boeing 787-8 | Prior to July 2014 agreement with Boeing
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered	7
Capital Addition Purchase Commitments | United Airlines, Inc. | Boeing 787-9
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered	2
Capital Addition Purchase Commitments | United Airlines, Inc. | Embraer 175 aircraft
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered	15
Capital Addition Purchase Commitments | United Airlines, Inc. | Boeing 787-10 | July 2014 agreement with Boeing
Commitments and Contingencies [Line Items]
Number of aircraft expected to be delivered	7
Capital Addition Purchase Commitments | United Airlines, Inc. | Maximum
Commitments and Contingencies [Line Items]
New aircraft, scheduled delivery date	2025
Capital Addition Purchase Commitments | United Airlines, Inc. | Maximum | Boeing 787-8 | Prior to July 2014 agreement with Boeing
Commitments and Contingencies [Line Items]
New aircraft, scheduled delivery date	2018
Capital Addition Purchase Commitments | United Airlines, Inc. | Minimum
Commitments and Contingencies [Line Items]
New aircraft, scheduled delivery date	2014
Capital Addition Purchase Commitments | United Airlines, Inc. | Minimum | Boeing 787-8 | Prior to July 2014 agreement with Boeing
Commitments and Contingencies [Line Items]
New aircraft, scheduled delivery date	2017
Capital Addition Purchase Commitments | United Airlines, Inc. | Minimum | Boeing 787-10 | July 2014 agreement with Boeing
Commitments and Contingencies [Line Items]
New aircraft, scheduled delivery date	2018