Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2012

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

(in millions)	December 31, 2012			Level 1		Level 2			Level 3		Valuation Technique
Cash equivalents	$	2,176		$	2,176	$	—		$	—	(a)
Short-term investments	958			958		—			—		(a)
Restricted cash equivalents and investments	344			344		—			—		(a)
Long-term investments	208			100		27			81		(a)(b)
Hedge derivatives, net
Fuel hedge contracts	249			27		222			—		(a)(b)
Interest rate contracts	(66		)	—		(66		)	—		(a)(b)
Foreign currency exchange contracts	123			—		123			—		(a)

(in millions)	December 31, 2011			Level 1		Level 2			Level 3		Valuation Technique
Cash equivalents	$	2,357		$	2,357	$	—		$	—	(a)
Short-term investments	958			958		—			—		(a)
Restricted cash equivalents and investments	341			341		—			—		(a)
Long-term investments	188			55		24			109		(a)(b)
Hedge derivatives, net
Fuel hedge contracts	70			—		70			—		(a)(b)
Interest rate contracts	(91		)	—		(91		)	—		(a)(b)
Foreign currency exchange contracts	(89		)	—		(89		)	—		(a)

⁽¹⁾  See Note 11, “Employee Benefit Plans”, for fair value of benefit plan assets.

Fair Value Measurements, Nonrecurring [Table Text Block]

Assets Measured at Fair Value on a Nonrecurring Basis

	Significant Unobservable Inputs (Level 3)
(in millions)	December 31, 2012		December 31, 2011		Valuation Technique
Goodwill(1)	$	9,794	$	9,794	(a)(b)
Indefinite-lived intangible assets(1) (see Note 6)	4,373		4,375		(a)(b)

⁽¹⁾  See Note 1, “Goodwill and Other Intangible Assets”, for a description of how these assets are tested for impairment.