Details of Pass Through Trusts (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended			9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Feb. 08, 2013 Class B Pass Through Certificates	Sep. 30, 2013 United Airlines, Inc.	Sep. 30, 2012 United Airlines, Inc.	Sep. 30, 2013 United Airlines, Inc. Class A Pass Through Certificates August 2013	Sep. 30, 2013 United Airlines, Inc. Class A Pass Through Certificates October 2012	Sep. 30, 2013 United Airlines, Inc. Class B Pass Through Certificates August 2013	Sep. 30, 2013 United Airlines, Inc. Class B Pass Through Certificates October 2012	Sep. 30, 2013 United Airlines, Inc. Class C Pass Through Certificates December 2012	Sep. 30, 2013 United Airlines, Inc. EETC
Debt Instrument [Line Items]
Principal			$ 123			$ 720	$ 712	$ 209	$ 132	$ 425	$ 2,198
Final expected distribution date						2025-08	2024-10	2021-08	2020-10	2018-04
Stated interest rate	8.00%	8.00%		8.00%	8.00%	4.30%	4.00%	5.375%	5.50%	6.125%
Total debt recorded							712		132	425	1,269
Proceeds received from issuance of debt	819	86		819	86		465		86	147	698
Remaining proceeds from issuance of debt to be received in future periods						$ 720		$ 209			$ 929