Leases and Capacity Purchase Agreements - Additional Information (Detail) (USD $)	12 Months Ended						1 Months Ended	12 Months Ended				1 Months Ended	12 Months Ended							12 Months Ended		1 Months Ended	12 Months Ended				1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012 Aircraft	Dec. 31, 2011	Dec. 31, 2013 Minimum	Dec. 31, 2013 Maximum	Dec. 31, 2013 10% increase or decrease in scheduled block hours Capacity Purchase Agreements	Apr. 30, 2013 United Airlines, Inc.	Dec. 31, 2013 United Airlines, Inc.	Dec. 31, 2012 United Airlines, Inc.	Dec. 31, 2011 United Airlines, Inc.	Dec. 31, 2013 United Airlines, Inc. Variable Interest Entity, Not Primary Beneficiary	Apr. 30, 2013 United Airlines, Inc. Capacity Purchase Agreements Aircraft	Dec. 31, 2013 United Airlines, Inc. Capacity Purchase Agreements Aircraft	Dec. 31, 2013 United Airlines, Inc. Regional Aircraft	Dec. 31, 2012 United Airlines, Inc. Regional Aircraft	Dec. 31, 2011 United Airlines, Inc. Regional Aircraft	Dec. 31, 2013 United Airlines, Inc. Revaluation of Liabilities	Dec. 31, 2012 United Airlines, Inc. Revaluation of Liabilities	Dec. 31, 2011 United Airlines, Inc. Revaluation of Liabilities	Dec. 31, 2013 United Airlines, Inc. Minimum	Dec. 31, 2013 United Airlines, Inc. Maximum	May 31, 2013 Sky West Incorporation Capacity Purchase Agreements Aircraft Seat	Dec. 31, 2013 Aircraft Operating Leases		Dec. 31, 2013 Aircraft Operating Leases Minimum	Dec. 31, 2013 Aircraft Operating Leases Maximum	Nov. 30, 2013 Lease Amendment United Airlines, Inc.
Operating Leased Assets [Line Items]
Operating lease term																									6 years	26 years	4 years
Operating lease expiration date, in years							2033																		2014	2024
Operating lease extended expiration year																							2041
Operating leases obligations											$ 1,600,000,000												$ 7,790,000,000	[1]
Additional investment commitments							150,000,000																				450,000,000
Nonaircraft rent expense								1,300,000,000	1,300,000,000	1,300,000,000
Regional capacity purchase expense	2,419,000,000	2,470,000,000	2,403,000,000					2,419,000,000	2,470,000,000	2,403,000,000				428,000,000	463,000,000	498,000,000
Lease Fair Value Adjustment, Remaining Lease Term																				1 year	11 years
Net accretion amounts																	173,000,000	240,000,000	227,000,000
Number of regional aircraft		133										30	572									40
Airline capacity purchase arrangements, expiration year													2027
Number of seats in the aircraft																						76
Number of aircraft purchase												30
Projected inflation rate				1.38%	2.50%
Scheduled block hours increase (decrease) percentage						10.00%
Change in cash obligation						$ 159,000,000
Cash obligation increase (decrease) percentage						8.20%

[1] The operating lease payments presented above include future payments of $103 million related to 25 nonoperating aircraft as of December 31, 2013.