Activity for "Level Three" Financial Assets and Financial Liabilities (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended						3 Months Ended				6 Months Ended				3 Months Ended		6 Months Ended		3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended
	Jun. 30, 2011 United Continental Holdings Inc Auction Rate Securities		Jun. 30, 2012 United Continental Holdings Inc Auction Rate Securities		Jun. 30, 2011 United Continental Holdings Inc Auction Rate Securities		Mar. 31, 2012 United Continental Holdings Inc Auction Rate Securities		Jun. 30, 2012 United Continental Holdings Inc EETC		Jun. 30, 2011 United Continental Holdings Inc EETC		Jun. 30, 2012 United Continental Holdings Inc EETC		Jun. 30, 2011 United Continental Holdings Inc EETC		Jun. 30, 2012 Continental Airlines Inc Auction Rate Securities	Jun. 30, 2011 Continental Airlines Inc Auction Rate Securities	Jun. 30, 2012 Continental Airlines Inc Auction Rate Securities	Jun. 30, 2011 Continental Airlines Inc Auction Rate Securities	Jun. 30, 2012 Continental Airlines Inc Convertible Debt Derivative Asset		Jun. 30, 2011 Continental Airlines Inc Convertible Debt Derivative Asset		Jun. 30, 2012 Continental Airlines Inc Convertible Debt Derivative Asset		Jun. 30, 2011 Continental Airlines Inc Convertible Debt Derivative Asset		Jun. 30, 2012 Continental Airlines Inc Convertible Debt Option Liability		Jun. 30, 2011 Continental Airlines Inc Convertible Debt Option Liability		Jun. 30, 2012 Continental Airlines Inc Convertible Debt Option Liability		Jun. 30, 2011 Continental Airlines Inc Convertible Debt Option Liability
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 120	[1]	$ 113	[1]	$ 119	[1]	$ 112	[1]	$ 62	[1]	$ 63	[1]	$ 60	[1]	$ 66	[1]	$ 112	$ 120	$ 113	$ 119	$ 231	[2]	$ 262	[2]	$ 193	[2]	$ 286	[2]	$ (119)	[2]	$ (152)	[2]	$ (95)	[2]	$ (164)	[2]
Settlements													(2)	[1]	(2)	[1]
Sales																						[2]		[2]		[2]		[2]		[2]		[2]		[2]		[2]
Reported in earnings-unrealized	1	[1]	(1)	[1]	1	[1]												1	(1)	1	58	[2]	(11)	[2]	96	[2]	(35)	[2]	(28)	[2]	9	[2]	(52)	[2]	21	[2]
Reported in other comprehensive income					1	[1]			1	[1]	2	[1]	5	[1]	1	[1]				1
Ending Balance	$ 121	[1]	$ 112	[1]	$ 121	[1]	$ 112	[1]	$ 63	[1]	$ 65	[1]	$ 63	[1]	$ 65	[1]	$ 112	$ 121	$ 112	$ 121	$ 289	[2]	$ 251	[2]	$ 289	[2]	$ 251	[2]	$ (147)	[2]	$ (143)	[2]	$ (147)	[2]	$ (143)	[2]

[1] For 2012 and 2011, United's only Level 3 recurring measurements are the above EETCs.

[2] These derivatives are not designated as hedges. The Convertible Debt Supplemental Derivative Asset is classified in "Other Asset - Other, net", and the Convertible Debt Conversion Option Liability is classified in "Other liabilities and deferred credits - Other" in Continental's consolidated balance sheets. The earnings impact is classified in "Nonoperating income (expense) - Miscellaneous, net" in Continental's statements of consolidated operations.