Hedging Activities (Description Of Derivative Instruments) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010	Sep. 30, 2011		Sep. 30, 2010
Derivative [Line Items]
Nonoperating income (expense)	$ (275)		$ (154)	$ (786)		$ (481)
Second Half Of 2011 [Member] | Maximum [Member]
Derivative [Line Items]
Percentage of Expected Consumption	56.00%	[1]		56.00%	[1]
Second Half Of 2011 [Member] | Maximum [Member] | Aircraft Fuel Swaps [Member]
Derivative [Line Items]
Percentage of Expected Consumption	4.00%	[1]		4.00%	[1]
Weighted Average Price (per gallon)	3.03	[1]		3.03	[1]
Second Half Of 2011 [Member] | Maximum [Member] | Aircraft Fuel Call Options [Member]
Derivative [Line Items]
Percentage of Expected Consumption	2.00%	[1]		2.00%	[1]
Weighted Average Price (per gallon)	3.21	[1]		3.21	[1]
Second Half Of 2011 [Member] | Maximum [Member] | Heating Oil Swaps [Member]
Derivative [Line Items]
Percentage of Expected Consumption	4.00%	[1]		4.00%	[1]
Weighted Average Price (per gallon)	2.93	[1]		2.93	[1]
Second Half Of 2011 [Member] | Maximum [Member] | Heating Oil Call Options [Member]
Derivative [Line Items]
Percentage of Expected Consumption	5.00%	[1]		5.00%	[1]
Weighted Average Price (per gallon)	3.23	[1]		3.23	[1]
Second Half Of 2011 [Member] | Maximum [Member] | Heating Oil Collars [Member]
Derivative [Line Items]
Percentage of Expected Consumption	19.00%	[1]		19.00%	[1]
Weighted Average Price (per gallon)	3.27	[1]		3.27	[1]
Second Half Of 2011 [Member] | Maximum [Member] | WTI Crude Oil Swaps [Member]
Derivative [Line Items]
Percentage of Expected Consumption	10.00%	[1]		10.00%	[1]
Weighted Average Price (per gallon)	2.19	[1]		2.19	[1]
Second Half Of 2011 [Member] | Maximum [Member] | WTI Crude Oil Call Options [Member]
Derivative [Line Items]
Percentage of Expected Consumption	12.00%	[1]		12.00%	[1]
Weighted Average Price (per gallon)	2.35	[1]		2.35	[1]
Second Half Of 2011 [Member] | Minimum [Member]
Derivative [Line Items]
Percentage of Expected Consumption	37.00%	[1]		37.00%	[1]
Second Half Of 2011 [Member] | Minimum [Member] | Aircraft Fuel Swaps [Member]
Derivative [Line Items]
Percentage of Expected Consumption	4.00%	[1]		4.00%	[1]
Weighted Average Price (per gallon)	3.03	[1]		3.03	[1]
Second Half Of 2011 [Member] | Minimum [Member] | Heating Oil Swaps [Member]
Derivative [Line Items]
Percentage of Expected Consumption	4.00%	[1]		4.00%	[1]
Weighted Average Price (per gallon)	2.93	[1]		2.93	[1]
Second Half Of 2011 [Member] | Minimum [Member] | Heating Oil Collars [Member]
Derivative [Line Items]
Percentage of Expected Consumption	19.00%	[1]		19.00%	[1]
Weighted Average Price (per gallon)	2.63	[1]		2.63	[1]
Second Half Of 2011 [Member] | Minimum [Member] | WTI Crude Oil Swaps [Member]
Derivative [Line Items]
Percentage of Expected Consumption	10.00%	[1]		10.00%	[1]
Weighted Average Price (per gallon)	2.19	[1]		2.19	[1]
First Half Of 2012 [Member]
Derivative [Line Items]
Hedging percentage of fuel consumption				34.00%
Aircraft Fuel Hedges [Member]
Derivative [Line Items]
Nonoperating income (expense)	$ 56			$ 87

[1] As of September 30, 2011, UAL had also hedged 34% of projected first half 2012 fuel consumption.