Earnings Per Share Data (Tables)

3 Months Ended

Mar. 31, 2013

Earnings Per Share [Abstract]

Earnings Per Share

The following table reconciles the basic earnings per share computation to the diluted earnings per share computation (in millions, except share and per share amounts):

	Three Months Ended
	March 31,
	2013		2012
Net income available to common stockholders for purposes of computing basic and diluted earnings per share	$	103.7	$	74.9
Weighted-average number of shares outstanding (in thousands):
Basic shares	109,907		109,622
Effect of dilution	358		374
Diluted shares	110,265		109,996
Earnings per share:
Basic earnings per share	$	0.94	$	0.68
Diluted earnings per share	$	0.94	$	0.68
Potentially dilutive shares excluded from the calculation (in thousands):
Stock options excluded as their inclusion would be anti-dilutive	57		93