Hedging Activities (Projected Fuel Requirements) (Details)	12 Months Ended
	Dec. 31, 2011
Derivative [Line Items]
Hedging percentage of fuel consumption	47.00%
Maximum [Member]
Derivative [Line Items]
Percentage of Expected Consumption	31.00%	[1]
Maximum [Member] | Heating Oil Collars [Member]
Derivative [Line Items]
Percentage of Expected Consumption	11.00%	[1]
Weighted Average Price (per gallon)	3.13	[1]
Maximum [Member] | Heating Oil Call Options [Member]
Derivative [Line Items]
Percentage of Expected Consumption	7.00%	[1]
Weighted Average Price (per gallon)	3.22	[1]
Maximum [Member] | Brent Crude Oil Collars [Member]
Derivative [Line Items]
Percentage of Expected Consumption	6.00%	[1]
Weighted Average Price (per gallon)	2.74	[1]
Maximum [Member] | Diesel Fuel Collars [Member]
Derivative [Line Items]
Percentage of Expected Consumption	4.00%	[1]
Weighted Average Price (per gallon)	3.12	[1]
Maximum [Member] | Aircraft Fuel Swaps [Member]
Derivative [Line Items]
Percentage of Expected Consumption	1.00%	[1]
Weighted Average Price (per gallon)	2.90	[1]
Maximum [Member] | WTI Crude Oil Call Options [Member]
Derivative [Line Items]
Percentage of Expected Consumption	1.00%	[1]
Weighted Average Price (per gallon)	2.37	[1]
Maximum [Member] | WTI Crude Oil Swaps [Member]
Derivative [Line Items]
Percentage of Expected Consumption	1.00%	[1]
Weighted Average Price (per gallon)	2.25	[1]
Minimum [Member]
Derivative [Line Items]
Percentage of Expected Consumption	23.00%	[1]
Minimum [Member] | Heating Oil Collars [Member]
Derivative [Line Items]
Percentage of Expected Consumption	11.00%	[1]
Weighted Average Price (per gallon)	2.52	[1]
Minimum [Member] | Heating Oil Call Options [Member]
Derivative [Line Items]
Percentage of Expected Consumption	0.00%	[1]
Minimum [Member] | Brent Crude Oil Collars [Member]
Derivative [Line Items]
Percentage of Expected Consumption	6.00%	[1]
Weighted Average Price (per gallon)	1.91	[1]
Minimum [Member] | Diesel Fuel Collars [Member]
Derivative [Line Items]
Percentage of Expected Consumption	4.00%	[1]
Weighted Average Price (per gallon)	2.35	[1]
Minimum [Member] | Aircraft Fuel Swaps [Member]
Derivative [Line Items]
Percentage of Expected Consumption	1.00%	[1]
Weighted Average Price (per gallon)	2.90	[1]
Minimum [Member] | WTI Crude Oil Call Options [Member]
Derivative [Line Items]
Percentage of Expected Consumption	0.00%	[1]
Minimum [Member] | WTI Crude Oil Swaps [Member]
Derivative [Line Items]
Percentage of Expected Consumption	1.00%	[1]
Weighted Average Price (per gallon)	2.25	[1]

[1] Represents a hedge of approximately 47% of UAL's expected first quarter consumption with decreasing hedge coverage later throughout 2012.