Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2012

Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table summarizes assets and liabilities that are measured at fair value on a recurring basis as of June 30, 2012 and December 31, 2011:

	June 30, 2012						December 31, 2011
	Fair Value Asset (Liability)						Fair Value Asset (Liability)
(in millions)	Level 1		Level 2		Total		Level 1		Level 2			Total
Derivatives:
Assets	$	—	$	2.3	$	2.3	$	—	$	4.4		$	4.4
Liabilities		—		12.8		12.8		—		(8.6	)		(8.6	)
Available for sale securities		—		19.5		19.5		—		19.5			19.5