Note 6 - Net Income Per Common Share (Tables)

12 Months Ended

Apr. 30, 2014

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Years ended April 30,
	2014		2013		2012
Basic
Net income	$	126,820	$	103,814	$	114,694
Weighted average shares outstanding-basic		38,457,680		38,297,083		38,068,001
Basic earnings per common share	$	3.30	$	2.71	$	3.01
Diluted
Net income	$	126,820	$	103,814	$	114,694
Weighted-average shares outstanding-basic		38,457,680		38,297,083		38,068,001
Plus effect of stock options and restricted stock units		410,726		322,993		323,703
Weighted-average shares outstanding-diluted		38,868,406		38,620,076		38,391,704
Diluted earnings per common share	$	3.26	$	2.69	$	2.99