Earnings Per Share

3 Months Ended

Jul. 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 common shares outstanding during the period. Diluted earnings per share further includes the dilutive effect of stock-based compensation awards, including stock options, stock-settled stock appreciation rights, restricted stock units, deferred stock units, and shares of restricted stock. We calculate that dilutive effect using the “treasury stock method” (as defined by GAAP).

Some restricted shares have 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
	July 31
(Dollars in millions, except per share amounts)	2011		2012
Basic and diluted net income	$	118.1	$	147.5
Income allocated to participating securities		—		(0.1	)
Net income available to common stockholders	$	118.1	$	147.4
Share data (in thousands):
Basic average common shares outstanding		217,242		213,168
Dilutive effect of stock-based awards		1,559		1,630
Diluted average common shares outstanding		218,801		214,798
Basic earnings per share	$	0.54	$	0.69
Diluted earnings per share	$	0.54	$	0.69

We excluded common stock-based awards for approximately 582,000 shares and 561,000 shares from the calculation of diluted earnings per share for the periods ended July 31, 2011 and 2012, respectively, because they were not dilutive for those periods under the treasury stock method.

As discussed in Note 11, all previously reported share and per share amounts have been restated in the accompanying financial statements and related notes to reflect the stock split.