Commitments and Contingencies - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended
	Apr. 30, 2013	Jun. 30, 2013	Jun. 30, 2013 United Airlines, Inc. Employee	Jun. 30, 2013 Floating Rate Debt	Jun. 30, 2013 Notes payable, fixed interest rates of 4.00% to 12.00% (weighted average rate of 6.96% as of December 31, 2012), payable through 2024	Jun. 30, 2013 Loans And Leases From Non U S Entities	Jun. 17, 2013 Boeing 787-10 Aircraft	Jun. 19, 2013 Airbus A350-1000 aircraft Aircraft	May 31, 2013 Embraer EMB175 aircraft Aircraft	Apr. 30, 2013 Embraer EMB175 aircraft Aircraft	Jun. 30, 2013 Tax-exempt special facilities revenue bonds	Mar. 27, 2013 Revolving Credit Facility	Jun. 30, 2013 Capital Addition Purchase Commitments United Airlines, Inc. Aircraft	Jun. 30, 2013 Capital Addition Purchase Commitments Boeing 737 Aircraft	Jun. 30, 2013 Capital Addition Purchase Commitments Boeing 737 United Airlines, Inc. Aircraft	Jun. 30, 2013 Capital Addition Purchase Commitments Boeing 787-10 United Airlines, Inc. Aircraft	Jun. 30, 2013 Capital Addition Purchase Commitments Airbus A350-1000 aircraft United Airlines, Inc. Aircraft	Jun. 30, 2013 Capital Addition Purchase Commitments Embraer EMB175 aircraft United Airlines, Inc. Aircraft	Jun. 30, 2013 Capital Addition Purchase Commitments Boeing 737-900ER AirCraft Aircraft	Jun. 30, 2013 Capital Addition Purchase Commitments Boeing 737-900ER AirCraft United Airlines, Inc. Aircraft	Jun. 30, 2013 Capital Addition Purchase Commitments Boeing 787-8 Aircraft	Jun. 19, 2013 Minimum Airbus A350-1000 aircraft	Apr. 30, 2013 Minimum Embraer EMB175 aircraft	Jun. 30, 2013 Minimum Tax-exempt special facilities revenue bonds	Jun. 30, 2013 Minimum Capital Addition Purchase Commitments United Airlines, Inc.	Jun. 30, 2013 Minimum Capital Addition Purchase Commitments Boeing 737	Jun. 30, 2013 Maximum Y	Jun. 30, 2013 Maximum Loans And Leases From Non U S Entities Y	Jun. 19, 2013 Maximum Airbus A350-1000 aircraft	Apr. 30, 2013 Maximum Embraer EMB175 aircraft	Jun. 30, 2013 Maximum Tax-exempt special facilities revenue bonds	Jun. 30, 2013 Maximum Capital Addition Purchase Commitments United Airlines, Inc.	Jun. 30, 2013 Maximum Capital Addition Purchase Commitments Boeing 737
Commitments and Contingencies [Line Items]
Number of new aircraft under purchase rights and options							10	25
New aircraft, scheduled delivery date																						2018	2014			2018			2024	2015		2025	2025
Number of new aircraft committed to purchase									40	30			199	100	75	59	35	30
New aircraft, scheduled delivery date																									Jul. 01, 2013
Number of aircraft delivered																				6
Number of aircraft expected to be delivered																2				12
Number of aircraft under financing arrangement expected to be delivered														1					14		1
Number of aircraft under financing arrangement delivered																			6
Number of aircraft under financing arrangement expected to be delivered during the reminder of 2013																			2
Lease extension signed with the Port Authority of New York and New Jersey	20 years
Commitment to invest an additional amount in facility upgrades at Newark	$ 150,000,000
Guarantor obligations, maximum exposure											1,900,000,000
Operating leases obligations											1,700,000,000
Capital leases obligations											180,000,000
Debt instrument, maturity year																								2015							2038
Debt instrument principal amount				2,000,000,000	317,000,000	2,200,000,000
Debt instrument, remaining terms (years)																											9	8
Borrowing capacity under revolving credit facility												1,000,000,000
Capacity available under the revolving credit facility												$ 1,000,000,000
Number of employees			88,000
Percentage of employees represented by various U.S. labor organizations		80.00%