Earnings Per Share (Computation Of Earnings Per Share) (Details) (USD $) In Millions, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Net income	$ 653	$ 387	$ 978	$ 578
Less: Income allocable to participating securities	(2)		(3)	(1)
Earnings available to common stockholders	651	387	975	577
Basic weighted average shares outstanding	330	168	329	168
Earnings per share, basic	$ 1.97	$ 2.30	$ 2.96	$ 3.44
Earnings available to common stockholders including the effect of dilutive securities	663	413	1,026	643
Diluted weighted average shares outstanding	392	235	396	231
Earnings per share, diluted	$ 1.69	$ 1.75	$ 2.59	$ 2.78
UAL 4.5% Senior Limited Subordination Convertible Notes [Member]
Effect of convertible notes on basic earnings per share, amount	2	18	31	53
Effect of convertible notes on basic earnings per share, shares	5	22	13	22
Continental 4.5% Convertible Notes [Member]
Effect of convertible notes on basic earnings per share, amount	2		7
Effect of convertible notes on basic earnings per share, shares	12		12
UAL 5% Senior Convertible Notes [Member]
Effect of convertible notes on basic earnings per share, amount		4
Effect of convertible notes on basic earnings per share, shares		3
Potentially dilutive shares excluded from diluted per share amounts				3
Continental 6% Convertible Junior Subordinated Debentures [Member]
Effect of convertible notes on basic earnings per share, amount	4
Effect of convertible notes on basic earnings per share, shares	4
Potentially dilutive shares excluded from diluted per share amounts			4
UAL 6% Senior Notes [Member]
Effect of convertible notes on basic earnings per share, amount	$ 4	$ 4	$ 13	$ 13
Effect of convertible notes on basic earnings per share, shares	40	40	40	40
Restricted Shares And Units And Stock Options [Member]
Effect of restricted stock units and employee stock options	1	2	2	1
Restricted Stock And Stock Options [Member]
Potentially dilutive shares excluded from diluted per share amounts	7	5	6	5