COMPREHENSIVE INCOME (LOSS) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
AOCI Beginning Balance	$ (224)
Changes in fair value, other	144
Reclassification to earnings, other	23
AOCI Ending Balance	(57)
Net Income	98	5
Other Comprehensive Income (Loss), Net of Tax	2	3
Total comprehensive income	265	346
Deferred taxes on unrealized gain (loss) on other	2	2
Fuel hedge derivatives [Member]
AOCI Beginning Balance	(183)
Changes in fair value, derivatives	136
Reclassification to earnings, derivatives	23
AOCI Ending Balance	(24)
Unrealized gain (loss) on derivatives, net of tax	159	331
Deferred taxes on unrealized gain (loss) on derivatives	99	207
Interest Rate Swap [Member]
AOCI Beginning Balance	(66)
Changes in fair value, derivatives	6
AOCI Ending Balance	(60)
Unrealized gain (loss) on derivatives, net of tax	6	7
Deferred taxes on unrealized gain (loss) on derivatives	4	4
Other [Member]
AOCI Beginning Balance	25
Changes in fair value, other	2
AOCI Ending Balance	$ 27