Details of Pass Through Trusts (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Debt Instrument [Line Items]
Proceeds received from issuance of debt	$ 395	$ 520
United Airlines, Inc.
Debt Instrument [Line Items]
Proceeds received from issuance of debt	395	520
United Airlines, Inc. | Class A Pass Through Certificates | April 2014
Debt Instrument [Line Items]
Principal	736
Final expected distribution date	2026-04
Stated interest rate	4.00%
Total debt recorded	248
Proceeds received from issuance of debt	248
Remaining proceeds from issuance of debt to be received in future periods	488
United Airlines, Inc. | Class A Pass Through Certificates | August 2013
Debt Instrument [Line Items]
Principal	720
Final expected distribution date	2025-08
Stated interest rate	4.30%
Total debt recorded	720
Proceeds received from issuance of debt	567
United Airlines, Inc. | Class B Pass Through Certificates | April 2014
Debt Instrument [Line Items]
Principal	213
Final expected distribution date	2022-04
Stated interest rate	4.75%
Total debt recorded	72
Proceeds received from issuance of debt	72
Remaining proceeds from issuance of debt to be received in future periods	141
United Airlines, Inc. | Class B Pass Through Certificates | August 2013
Debt Instrument [Line Items]
Principal	209
Final expected distribution date	2021-08
Stated interest rate	5.375%
Total debt recorded	209
Proceeds received from issuance of debt	165
United Airlines, Inc. | EETC
Debt Instrument [Line Items]
Principal	1,878
Total debt recorded	1,249
Proceeds received from issuance of debt	1,052
Remaining proceeds from issuance of debt to be received in future periods	$ 629