Earnings Per Share

9 Months Ended

Jan. 31, 2012

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 stock 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. Certain restricted shares contain non-forfeitable rights to dividends declared on common stock. As a result, these 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 January 31,					Nine Months Ended January 31,
(Dollars in millions, except per share amounts)	2011			2012		2011			2012
Net income	$	140.7		$	133.1	$	406.1		$	408.7
Income allocated to participating securities (restricted shares)		(0.1	)		—		(0.4	)		(0.1	)
Net income available to common stockholders	$	140.6		$	133.1	$	405.7		$	408.6
Share data (in thousands):
Basic average common shares outstanding		145,061			141,928		145,787			143,317
Dilutive effect of stock options, SSARs, RSUs, and DSUs		979			1,072		883			1,029
Diluted average common shares outstanding		146,040			143,000		146,670			144,346
Basic earnings per share	$	0.97		$	0.94	$	2.78		$	2.85
Diluted earnings per share	$	0.96		$	0.93	$	2.77		$	2.83

SSARs for approximately 403,000 common shares and 387,000 common shares were excluded from the calculation of diluted earnings per share for the three months ended January 31, 2011 and 2012, respectively. SSARs for approximately 413,000 common shares and 388,000 common shares were excluded from the calculation of diluted earnings per share for the nine months ended January 31, 2011 and 2012, respectively. The SSARs were excluded because they were not dilutive for those periods under the treasury stock method.