Projected Fuel Requirements (Parenthetical) (Detail)	3 Months Ended
Jun. 30, 2012
Derivative [Line Items]
Hedging percentage of fuel consumption	15.00%

Percentage of Fuel Hedged by Price Risk Derivatives

No definition available.

Name:	ual_PercentageOfFuelHedgedByPriceRiskDerivatives
Namespace Prefix:	ual_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration