FAIR VALUE MEASUREMENTS (TABLES)

12 Months Ended

Dec. 31, 2012

Fair Value Disclosures [Abstract]

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

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

December 31, 2012	Level 1		Level 2			Total
Assets
Marketable securities
U.S. government 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
Fuel hedge contracts
Call options	—		65			65
Liabilities
Derivative instruments
Fuel hedge contracts
Swap agreements	—		(1		)	(1		)
Interest rate swap agreements	—		(33		)	(33		)

December 31, 2011	Level 1		Level 2			Total
Assets
Marketable securities
U.S. government securities	$	296	$	—		$	296
Foreign government bonds	—		25			25
Asset-back securities	—		58			58
Mortgage-back securities	—		125			125
Corporate notes and bonds	—		523			523
Municipal securities	—		12			12
Derivative instruments
Fuel hedge contracts
Call options	—		117			117
Liabilities
Derivative instruments
Fuel hedge contracts
Swap agreements	—		(10		)	(10		)
Interest rate swap agreements	$	—	$	(29	)	$	(29	)

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 as of December 31 (in millions):

	2012		2011
Carrying Amount	$	844	$	1,003
Fair value	915		1,076