Earnings Per Share

6 Months Ended

Jun. 30, 2011

Earnings Per Share

Earnings Per Share

4. Earnings Per Share

The Company's basic earnings per share calculations are based on the weighted average number of common shares outstanding during the year. Shares of restricted stock are included in the computation of both basic and diluted earnings per share. Potentially dilutive securities include outstanding stock options, restricted share units and deferred stock units. The dilutive effect of potentially dilutive securities is reflected in diluted earnings per common share by application of the treasury method. Diluted earnings per share gives effect to all potentially dilutive common shares outstanding during the year.

	Three Months Ended June 30,				Six Months Ended June 30,
(in thousands, except per share data)	2011		2010		2011		2010
Net income attributable to common shareholders	$	50,437	$	40,041	$	98,904	$	73,275
Average basic shares outstanding		58,173		58,909		58,259		58,777
Effect of dilutive stock options		1,175		985		1,198		939
Average diluted shares outstanding		59,348		59,894		59,457		59,716
Earnings per basic share	$	0.87	$	0.68	$	1.70	$	1.25
Earnings per diluted share	$	0.85	$	0.67	$	1.66	$	1.23

The computation of diluted earnings per share excludes the effect of the potential exercise of stock options when the average market price of the common stock is lower than the exercise price of the related stock options during the period (1.0 million and 2.4 million average options for the second quarter of 2011 and 2010, respectively, and 0.7 million and 2.9 million average options for the first half of 2011 and 2010, respectively).