Earnings per Share (Tables)

12 Months Ended

Apr. 30, 2011

Earnings Per Share (Tables) [Abstract]

Computation of Earnings Per Common Share

The following table sets forth the computation of net income per common share and net income per common share — assuming dilution.

	Year Ended April 30,
	2011		2010		2009
Computation of net income per share:
Net income	$	479,482	$	494,138	$	265,953
Net income allocated to participating securities		4,692		4,321		1,944
Net income allocated to common stockholders	$	474,790	$	489,817	$	264,009
Weighted-average common shares outstanding		117,009,362		117,911,160		84,823,849
Net income per common share	$	4.06	$	4.15	$	3.11

Computation of Earnings Per Common Share - assuming dilution

Computation of net income per share — assuming dilution:
Net income	$	479,482	$	494,138	$	265,953
Net income allocated to participating securities		4,690		4,318		1,947
Net income allocated to common stockholders	$	474,792	$	489,820	$	264,006
Weighted-average common shares outstanding		117,009,362		117,911,160		84,823,849
Dilutive effect of stock options		110,335		130,011		98,938
Weighted-average common shares outstanding — assuming dilution		117,119,697		118,041,171		84,922,787
Net income per common share — assuming dilution	$	4.05	$	4.15	$	3.11

Weighted-average common shares, basic and diluted

The following table reconciles the weighted-average common shares used in the basic and diluted earnings per share disclosures to the total weighted-average shares outstanding.

	Year Ended April 30,
	2011		2010		2009
Weighted-average common shares outstanding		117,009,362		117,911,160		84,823,849
Weighted-average participating shares outstanding		1,156,389		1,040,274		624,743
Weighted-average shares outstanding		118,165,751		118,951,434		85,448,592
Dilutive effect of stock options		110,335		130,011		98,938
Weighted-average shares outstanding — assuming dilution		118,276,086		119,081,445		85,547,530