Fair Value Measurement (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2012

Dec. 31, 2011

Fair Value Measurement Abstract

Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block]

Assets and liabilities measured at fair value at March 31, 2012 were as follows:

	Fair value measurements						Total fair value
In millions	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Recurring fair value measurements
Assets:
Marketable securities	$	12.9	$	—	$	—	$	12.9
Derivative instruments	—		9.6		—		9.6
Total asset recurring fair value measurements	$	12.9	$	9.6	$	—	$	22.5
Liabilities:
Derivative instruments	$	—	$	11.3	$	—	$	11.3
Total liability recurring fair value measurements	$	—	$	11.3	$	—	$	11.3
Nonrecurring fair value measurements
Assets:
Cash and cash equivalents	$	1,089.5	$	—	$	—	$	1,089.5
Total asset nonrecurring fair value measurements	$	1,089.5	$	—	$	—	$	1,089.5
Liabilities:
Total debt	$	—	$	4,544.2	$	—	$	4,544.2
Total liability nonrecurring fair value measurements	$	—	$	4,544.2	$	—	$	4,544.2

Assets and liabilities measured at fair value at December 31, 2011 were as follows:

	Fair value measurements						Total fair value
In millions	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Recurring fair value measurements
Assets:
Marketable securities	$	10.4	$	—	$	—	$	10.4
Derivative instruments	—		9.3		—		9.3
Total asset recurring fair value measurements	$	10.4	$	9.3	$	—	$	19.7
Liabilities:
Derivative instruments	$	—	$	22.2	$	—	$	22.2
Total liability recurring fair value measurements	$	—	$	22.2	$	—	$	22.2
Nonrecurring fair value measurements
Assets:
Cash and cash equivalents	$	1,160.7	$	—	$	—	$	1,160.7
Total asset nonrecurring fair value measurements	$	1,160.7	$	—	$	—	$	1,160.7
Liabilities:
Total debt	$	—	$	4,359.2	$	—	$	4,359.2
Total liability nonrecurring fair value measurements	$	—	$	4,359.2	$	—	$	4,359.2