Earnings Per Share

12 Months Ended

Dec. 31, 2011

Earnings Per Share [Abstract]

Earnings Per Share

14.   Earnings Per Share

The Company uses the two class method to calculate earnings per share (EPS).  The two class method is an earnings allocation formula that treats a participating security as having rights to earnings that otherwise would have been available to common shareholders.  Under the two class method, earnings for a period are allocated between common shareholders and participating security holders based on their respective rights to receive dividends as if all undistributed book earnings for the period were distributed.  Basic EPS is computed by dividing net income attributable to only the common shareholders by the weighted-average number of common shares outstanding for the period.  Diluted EPS includes the impact of stock options and other equity based instruments to the extent the effect is dilutive.

The following table illustrates the basic and dilutive EPS calculations for the three years ended December 31, 2011:

	Year Ended December 31,
(In millions, except per share data)	2011		2010		2009
Numerator:
Numerator for basic EPS	$	141.6	$	133.6	$	132.9
Add back earnings attributable to participating securities		-		0.1		0.2
Reported net income (Numerator for Diluted EPS)	$	141.6	$	133.7	$	133.1
Denominator:
Weighted average common shares outstanding (Basic EPS)		81.8		81.2		80.7
Conversion of share based compensation arrangements		-		0.1		0.3
Adjusted weighted average shares outstanding and
assumed conversions outstanding (Diluted EPS)		81.8		81.3		81.0
Basic earnings per share	$	1.73	$	1.65	$	1.65
Diluted earnings per share	$	1.73	$	1.64	$	1.64

For the year ended December 31, 2011, there were no antidilutive options outstanding.  For the years ended December 31, 2010 and 2009, options to purchase 308,800 and 837,100, respectively, of additional shares of the Company's common stock were outstanding, but were not included in the computation of diluted EPS because their effect would be antidilutive.  The exercise prices for these options ranged from $24.90 to $27.15 and $23.19 to $27.15 for the years ended December 31, 2010 and 2009, respectively.