Condensed Consolidated Statement of Operations (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
OPERATING REVENUES [Abstract]
Passenger	$ 4,014	$ 3,032	$ 10,829	$ 8,544
Freight	35	31	103	94
Other	262	129	618	352
Total operating revenues	4,311	3,192	11,550	8,990
OPERATING EXPENSES [Abstract]
Salaries, wages, and benefits	1,146	938	3,226	2,748
Fuel and oil	1,586	926	4,150	2,681
Maintenance materials and repairs	272	196	717	556
Aircraft Rental	90	43	214	135
Landing fees and other rentals	257	210	705	606
Depreciation, Depletion and Amortization, Nonproduction	191	161	523	469
Acquisition and integration	22	1	97	1
Other operating expenses	522	362	1,372	1,022
Total operating expenses	4,086	2,837	11,004	8,218
OPERATING INCOME (LOSS)	225	355	546	772
OTHER EXPENSES (INCOME) [Abstract]
Interest expense	50	43	143	126
Capitalized interest	(3)	(5)	(8)	(15)
Interest income	(1)	(2)	(8)	(9)
Other Nonoperating Income (Expense)	405	(13)	351	138
Total other expenses	451	23	478	240
INCOME (LOSS) BEFORE INCOME TAXES	(226)	332	68	532
PROVISION (BENEFIT) FOR INCOME TAXES	(86)	127	42	204
Net income (loss)	$ (140)	$ 205	$ 26	$ 328
Net income per share, basic	$ (0.18)	$ 0.27	$ 0.03	$ 0.44
Net income per share, diluted	$ (0.18)	$ 0.27	$ 0.03	$ 0.44
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Weighted average shares outstanding, basic	792	746	773	745
Weighted Average Number of Shares Outstanding, Diluted	792	747	774	746
Cash dividends declared per common share	$ 0.0045	$ 0.0045	$ 0.0135	$ 0.0135