Condensed Consolidated Statement of Comprehensive Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
OPERATING REVENUES:
Passenger	$ 4,380	$ 4,347	$ 8,218	$ 8,097
Freight	43	42	82	79
Other	220	227	427	430
Total operating revenues	4,643	4,616	8,727	8,606
OPERATING EXPENSES:
Salaries, wages, and benefits	1,298	1,222	2,481	2,363
Fuel and oil	1,489	1,577	2,946	3,087
Maintenance materials and repairs	281	291	571	562
Aircraft rentals	92	90	185	178
Landing fees and other rentals	292	260	558	513
Depreciation and amortization	213	202	422	403
Acquisition and integration	26	11	39	24
Other operating expenses	519	503	1,022	995
Total operating expenses	4,210	4,156	8,224	8,125
OPERATING INCOME	433	460	503	481
OTHER EXPENSES (INCOME):
Interest expense	33	38	62	77
Capitalized interest	(8)	(6)	(13)	(11)
Interest income	(2)	(2)	(3)	(3)
Other (gains) losses, net	47	62	1	(109)
Total other expenses (income)	70	92	47	(46)
INCOME BEFORE INCOME TAXES	363	368	456	527
PROVISION FOR INCOME TAXES	139	140	173	200
NET INCOME	224	228	283	327
NET INCOME PER SHARE, BASIC (in dollars per share)	$ 0.31	$ 0.30	$ 0.39	$ 0.43
NET INCOME PER SHARE, DILUTED (in dollars per share)	$ 0.31	$ 0.30	$ 0.39	$ 0.43
COMPREHENSIVE INCOME (LOSS)	$ 87	$ (35)	$ 154	$ 231
WEIGHTED AVERAGE SHARES OUTSTANDING
Basic (in shares)	714	757	719	764
Diluted (in shares)	722	764	727	771
Cash dividends declared per common share (in dollars per share)	$ 0.0400	$ 0.0100	$ 0.0500	$ 0.0145