Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2015

Fair Value Disclosures [Abstract]

Assets (liabilities) measured at fair value on a recurring basis

Assets (Liabilities) Measured at Fair Value on a Recurring Basis

(in millions)	September 30, 2015			Level 1		Level 2
Cash equivalents	$	1,824		$	1,824	$	—
Short-term investments
U.S. government and agency securities	124			71		53
Asset- and mortgage-backed securities	392			—		392
Corporate obligations	888			—		888
Other fixed income securities	38			—		38
Restricted cash equivalents and investments	46			46		—
Long-term investments	97			72		25
Hedge derivatives, net
Fuel hedge contracts	(835		)	122		(957		)
Interest rate contract	1			—		1
Foreign currency exchange contracts	92			—		92

(in millions)	December 31, 2014			Level 1			Level 2
Cash equivalents	$	1,612		$	1,612		$	—
Short-term investments
U.S. government and agency securities	59			—			59
Asset- and mortgage-backed securities	392			—			392
Corporate obligations	749			—			749
Other fixed income securities	17			—			17
Restricted cash equivalents and investments	37			37			—
Long-term investments	118			90			28
Hedge derivatives, net
Fuel hedge contracts	(1,848		)	(167		)	(1,681		)
Interest rate contract	(7		)	—			(7		)
Foreign currency exchange contracts	73			—			73