Condensed Consolidated Statements of Operations and Comprehensive Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Passenger Revenue [Abstract]
Passenger Revenue, Mainline	$ 5,876	$ 5,662
Passenger Revenue, Regional	1,457	1,564
Passenger Revenue	7,333	7,226
Cargo Revenue	238	244
Other Revenue, Net	929	943
Total operating revenue	8,500	8,413
Operating Expenses [Abstract]
Aircraft Fuel and Related Costs	2,289	2,233
Salaries and Related Costs	1,911	1,763
Contract Carrier Arrangements	1,399	1,375
Aircraft Maintenance, Materials and Outside Repairs	491	561
Depreciation and Amortization	405	386
Contracted Services	401	378
Passenger Commissions and Other Selling Expense	357	380
Landing Fees and Other Rents	323	305
Passenger Services	164	171
Aircraft Rent	60	75
Profit Sharing	20	0
Restructuring and Other Items	102	(12)
Other Cost and Expense, Operating	356	416
Total Operating Expenses	8,278	8,031
Operating Income (Loss)	222	382
Nonoperating Income (Expense) [Abstract]
Interest Expense, Net	(178)	(221)
Amortization of Debt Discount	(42)	(51)
Miscellaneous, Net	1	17
Nonoperating Income (Expense)	(219)	(255)
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	3	127
Income Tax Expense (Benefit)	4	(3)
Net income	7	124
Basic earnings per share	$ 0.01	$ 0.15
Diluted earnings per share	$ 0.01	$ 0.15
Comprehensive Income
Comprehensive Income	$ 158	$ 372