Schedule of Gain Loss on Derivative Instruments (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from AOCI into Income (Fuel Expense) (Effective Portion)	$ 38	$ (94)	$ 107	$ (526)
United Continental Holdings Inc
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income (Nonoperating Expense)	10		10
United Air Lines Inc
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from AOCI into Income (Fuel Expense) (Effective Portion)	23	(90)	55	(427)
Amount of Gain (Loss) Recognized in Income (Nonoperating Expense)	8		8
Continental Airlines Inc
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from AOCI into Income (Fuel Expense) (Effective Portion)	15	(4)	52	(99)
Amount of Gain (Loss) Recognized in Income (Nonoperating Expense)	2		2
Designated as Hedging Instrument | Cash Flow Hedging | United Continental Holdings Inc
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	133	(181)	(36)	112
Gain (Loss) Reclassified from AOCI into Income (Fuel Expense) (Effective Portion)	(38)	94	(107)	526
Amount of Gain (Loss) Recognized in Income (Nonoperating Expense) (Ineffective Portion)	2	(56)	(2)	(87)
Designated as Hedging Instrument | Cash Flow Hedging | United Air Lines Inc
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	77	(91)	(13)	145
Gain (Loss) Reclassified from AOCI into Income (Fuel Expense) (Effective Portion)	(23)	90	(55)	427
Amount of Gain (Loss) Recognized in Income (Nonoperating Expense) (Ineffective Portion)	1	(33)	(1)	(38)
Designated as Hedging Instrument | Cash Flow Hedging | Continental Airlines Inc
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	56	(90)	(23)	(33)
Gain (Loss) Reclassified from AOCI into Income (Fuel Expense) (Effective Portion)	(15)	4	(52)	99
Amount of Gain (Loss) Recognized in Income (Nonoperating Expense) (Ineffective Portion)	$ 1	$ (23)	$ (1)	$ (49)