DERIVATIVE INSTRUMENTS - FAIR VALUE OF HEDGE POSITIONS (DETAILS) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Derivative [Line Items]
Net cash received (paid) to for new positions and settlements	$ (7)	$ 0
B737-800 [Member]
Derivative [Line Items]
Operating Leases, Number of Units (in Aircraft)	6
Not Designated as Hedging Instrument [Member] | Fuel hedge contracts [Member]
Derivative [Line Items]
Fuel hedge contracts outstanding (in barrels)	264,000,000