Earnings Per Share Calculation (Tables)

12 Months Ended

Dec. 31, 2011

Earnings Per Share Calculation [Abstract]

Computation Of Weighted Average Shares Outstanding

(in millions)	2011		2010		2009
Weighted average shares outstanding:
Basic		88.1		89.0		84.1
Dilutive share-based awards		0.5		0.8		0.7
Diluted		88.6		89.8		84.8