AIRTRAN ACQUISITION AND RELATED MATTERS (Details) (USD $)	0 Months Ended	3 Months Ended
	May 02, 2011	Mar. 31, 2012
Acquisition of AirTran [Abstract]
Date entered into Merger Agreement	May 2, 2011
Business Combinations [Abstract]
Acquiree	AirTran Holdings, Inc.
Business Acquisition, Cost of Acquired Entity, Transaction Costs		$ 13,000,000
Business Acquisition, Purchase Price Allocation [Abstract]
Cash and cash equivalents	477,000,000
Restricted cash	6,000,000
Other current assets	234,000,000
Operating property and equipment	1,154,000,000
Goodwill	970,000,000
Deferred income taxes	162,000,000
Other identified intangibles	123,000,000
Other noncurrent assets	45,000,000
Long-term debt and capital leases, including current portion	(1,119,000,000)
Air traffic liability	(354,000,000)
Other liabilities assumed	(657,000,000)
Net assets acquired	1,041,000,000
Business Acquisition, Pro Forma Information [Abstract]
AirTran Revenues		678,000,000,000
AirTran Net income (loss)		$ (11,000,000)