Earnings Per Share

3 Months Ended

Jul. 31, 2011

Earnings Per Share [Abstract]

Earnings Per Share

4. Earnings Per Share

We calculate basic earnings per share by dividing net income available to common stockholders by the weighted average number of all unrestricted common shares outstanding during the period. Diluted earnings per share further includes the dilutive effect of stock options, stock-settled appreciation rights (“SSARs”), restricted stock units (“RSUs”), and deferred stock units (“DSUs”). We calculate that dilutive effect using the “treasury stock method” (as defined by GAAP).

We have granted restricted shares of common stock to certain employees as part of their compensation. These restricted shares, which have varying vesting periods, contain non-forfeitable rights to dividends declared on common stock. As a result, the unvested restricted shares are considered participating securities in the calculation of earnings per share.

The following table presents information concerning basic and diluted earnings per share:

	Three Months Ended
	July 31
(Dollars in millions, except per share amounts)	2010			2011
Basic and diluted net income	$	111.4		$	118.1
Income allocated to participating securities (restricted shares)		(0.1	)		—
Net income available to common stockholders	$	111.3		$	118.1
Share data (in thousands):
Basic average common shares outstanding		146,570			144,828
Dilutive effect of stock options, SSARs, RSUs, and DSUs		815			1,039
Diluted average common shares outstanding		147,385			145,867
Basic earnings per share	$	0.76		$	0.81
Diluted earnings per share	$	0.76		$	0.81

SSARs for approximately 428,000 common shares and 388,000 common shares were excluded from the calculation of diluted earnings per share for the periods ended July 31, 2010 and 2011, respectively, because they were not dilutive for those periods under the treasury stock method.