Details of Pass Through Trusts (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Debt Instrument [Line Items]
Proceeds received from issuance of debt	$ 147	$ 109
United Airlines, Inc.
Debt Instrument [Line Items]
Proceeds received from issuance of debt	147	109
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%
Remaining proceeds from issuance of debt to be received in future periods	736
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	548
Proceeds received from issuance of debt	395
Remaining proceeds from issuance of debt to be received in future periods	172
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%
Remaining proceeds from issuance of debt to be received in future periods	213
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	159
Proceeds received from issuance of debt	115
Remaining proceeds from issuance of debt to be received in future periods	50
United Airlines, Inc. | EETC
Debt Instrument [Line Items]
Principal	1,878
Total debt recorded	707
Proceeds received from issuance of debt	510
Remaining proceeds from issuance of debt to be received in future periods	$ 1,171