GENERAL AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - MILEAGE PLAN (DETAILS) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Mileage Plan [Line Items]
Other accrued liabilities	$ 612	$ 539
Other liabilities	308	334
Deferred revenue	335	443
Deferred revenue from Mileage Plan awards issued but not yet flown	31	39
Passenger revenues	4,267	4,030	3,708
Other-net revenues	584	516	501
Special Revenue	192	0	0
Total Operating Revenues	5,156	4,657	4,318
Liabilities From Mileage Plan [Member]
Mileage Plan [Line Items]
Other accrued liabilities	314	285
Other liabilities	19	17
Deferred revenue	323	428
Liabilities	656	730
Revenue From Mileage Plan [Member]
Mileage Plan [Line Items]
Passenger revenues	208	183	201
Other-net revenues	256	209	195
Special Revenue	192	0	0
Total Operating Revenues	656	392	396
Commission revenue	$ 213	$ 143	$ 138