Schedule of Derivative Credit Risk and Fair Value (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012
United Continental Holdings Inc
Derivative [Line Items]
Net derivative asset with counterparties	$ 33
Collateral posted by the Company with its counterparties		[1]
Potential loss related to the failure of the Company's counterparties to perform	34
United Air Lines Inc
Derivative [Line Items]
Net derivative asset with counterparties	24
Collateral posted by the Company with its counterparties		[1]
Potential loss related to the failure of the Company's counterparties to perform	25
Continental Airlines Inc
Derivative [Line Items]
Net derivative asset with counterparties	9
Collateral posted by the Company with its counterparties		[1]
Potential loss related to the failure of the Company's counterparties to perform	$ 9

[1] Classified as a current receivable.