Quarterly Financial Data (Unaudited) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended												12 Months Ended
	Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010		Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues	$ 8,399	[1]	$ 9,816	[1]	$ 9,153	[2]	$ 7,747	$ 7,789	$ 8,950	[3]	$ 8,168	$ 6,848	$ 35,115	$ 31,755	$ 28,063
Operating Income (Loss)	726	[1]	860	[1]	481	[2]	(92)	294	1,003	[3]	852	68	1,975	2,217	(324)
Net Income (Loss)	425	[1]	549	[1]	198	[2]	(318)	19	363	[3]	467	(256)	854	593	(1,237)
Earnings Per Share, Basic	$ 0.51	[1]	$ 0.66	[1]	$ 0.24	[2]	$ (0.38)	$ 0.02	$ 0.43	[3]	$ 0.56	$ (0.31)	$ 1.02	$ 0.71	$ (1.50)
Earnings Per Share, Diluted	$ 0.50	[1]	$ 0.65	[1]	$ 0.23	[2]	$ (0.38)	$ 0.02	$ 0.43	[3]	$ 0.55	$ (0.31)	$ 1.01	$ 0.70	$ (1.50)
Restructuring and Other Items [Member]
Quarterly Financial Information, Quarterly Charges and Credits, Amount Affecting Comparability					(144)
Gain (Loss) on Derivatives [Member]
Quarterly Financial Information, Quarterly Charges and Credits, Amount Affecting Comparability	164		(208)
Loss on extingushment of debt [Member]
Quarterly Financial Information, Quarterly Charges and Credits, Amount Affecting Comparability									(360)
Comair Fleet Reduction Initiative [Member]
Quarterly Financial Information, Quarterly Charges and Credits, Amount Affecting Comparability									$ (146)

[1] During the September 2011 quarter, we recorded $208 million of fuel hedge losses for mark-to-market adjustments recorded in periods other than the settlement period and in the December 2011 quarter, we recorded $164 million of fuel hedge gains for mark-to-market adjustments recorded in periods other than the settlement period.

[2] During the June 2011 quarter, we recorded $144 million of charges related to severance and related costs and our facilities consolidation and fleet assessments.

[3] During the September 2010 quarter, we recorded (1) a $360 million loss associated with the primarily non-cash loss on extinguishment of debt, including the write-off of unamortized debt discount and (2) a $146 million charge related to the Comair fleet reduction initiative.