Financial Instruments and Risk Management (Tables)

6 Months Ended

Jun. 30, 2012

Investments, All Other Investments [Abstract]

Components of aircraft fuel expense

The following table summarizes the components of aircraft fuel expense for the three and six months ended June 30, 2012 and 2011:

	Three Months Ended June 30,				Six Months Ended June 30,
	2012		2011		2012		2011
	(in millions)
Into-plane fuel cost	$	116.6	$	107.0	$	227.5	$	192.6
Changes in value and settlements of fuel hedge contracts	3.6		0.3		1.4		(4.3		)
Aircraft fuel expense	$	120.2	$	107.3	$	229.0	$	188.2