FAIR VALUE MEASUREMENTS (TABLES)

6 Months Ended

Jun. 30, 2013

Fair Value Disclosures [Abstract]

Fair Value, Measurement Inputs, Disclosure [Table Text Block]

Fair values of financial instruments on the consolidated balance sheet (in millions):

June 30, 2013	Level 1		Level 2			Total
Assets
Marketable securities
U.S. government and agency securities	$	409	$	—		$	409
Foreign government bonds	—		24			24
Asset-back securities	—		120			120
Mortgage-back securities	—		141			141
Corporate notes and bonds	—		657			657
Municipal securities	—		21			21
Derivative instruments
Call options	—		27			27
Liabilities
Derivative instruments
Fuel hedge contracts	—		(2		)	(2		)
Interest rate swap agreements	—		(20		)	(20		)

December 31, 2012	Level 1		Level 2			Total
Assets
Marketable securities
U.S. government and agency securities	$	272	$	—		$	272
Foreign government bonds	—		51			51
Asset-back securities	—		62			62
Mortgage-back securities	—		137			137
Corporate notes and bonds	—		585			585
Municipal securities	—		23			23
Derivative instruments
Call options	—		65			65
Liabilities
Derivative instruments
Fuel hedge contracts	—		(1		)	(1		)
Interest rate swap agreements	—		(33		)	(33		)

Fair Value, by Balance Sheet Grouping [Table Text Block]

Fixed-rate debt that is not carried at fair value on the consolidated balance sheet and the estimated fair value of long-term fixed-rate debt (in millions):

	June 30, 2013		December 31, 2012
Carrying amount	$	746	$	844
Fair value	807		915