MILEAGE PLAN MILEAGE PLAN (DETAILS) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Mileage Plan [Line Items]
Other accrued liabilities	$ 711		$ 711		$ 557
Deferred revenue	455		455		443
Other liabilities	318		318		334
Total passenger revenue	1,088	1,051	2,066	1,947
Other - net	138	132	268	251
Total Operating Revenues	1,256	1,214	2,390	2,253
Liabilities From Mileage Plan [Member]
Mileage Plan [Line Items]
Other accrued liabilities	319		319		285
Deferred revenue	442		442		428
Other liabilities	17		17		17
Liabilities	778		778		730
Revenue From Mileage Plan [Member]
Mileage Plan [Line Items]
Total passenger revenue	50	48	96	91
Other - net	56	55	110	103
Total Operating Revenues	$ 106	$ 103	$ 206	$ 194