MILEAGE PLAN MILEAGE PLAN (DETAILS) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Mileage Plan [Line Items]
Other accrued liabilities	$ 731		$ 629
Deferred revenue	382		374
Other liabilities	332		327
Passenger revenues	1,087	1,040
Other - net revenues	159	158
Liabilities From Mileage Plan [Member]
Mileage Plan [Line Items]
Other accrued liabilities	360		343
Deferred revenue	375		367
Other liabilities	19		20
Total	754		730
Revenue From Mileage Plan [Member]
Mileage Plan [Line Items]
Passenger revenues	64	55
Other - net revenues	76	73
Total Mileage Plan Revenues	$ 140	$ 128