Earnings Per Share

3 Months Ended

Mar. 31, 2013

Earnings Per Share [Abstract]

Earnings Per Share

Earnings Per Share

We compute basic earnings per share by dividing our net income available to our common stockholders by the weighted average number of shares of our common stock outstanding. Shares that we issued or reacquired during the period were appropriately weighted for the portion of the period that they were outstanding. Our diluted earnings per share reflect the impacts of our potentially dilutive securities, which include our convertible preferred stock and our equity compensation awards.

The following table shows the computation of our basic and diluted net income per common share (in millions, except per share amounts):

	Three Months Ended March 31
	2013		2012
Numerator:
Net income	$	27.1	$	30.3
Denominator:
Weighted average shares outstanding - basic	46.9		46.7
Effect of dilutive securities:
Equity compensation plans	0.7		0.7
Convertible preferred stock	0.1		0.1
Weighted average shares outstanding - diluted	47.7		47.5
Basic earnings per share	$	0.58	$	0.65
Diluted earnings per share	$	0.57	$	0.64