Earnings Per Share - (Tables)

3 Months Ended

Aug. 31, 2012

Earnings Per Share [Abstract]

Reconciliation of the numerators and the denominators of basic and diluted earnings per share

The following is a reconciliation of the numerators and the denominators of basic and diluted earnings per share computations:  

	Three Months Ended August 31,
	2012		2011
Income available to Class A and B common stockholders and vested restricted stock units (numerator):
Net income	$	6,029	$	4,703
Adjustments	—		—
Income on which basic and diluted earnings per share are calculated	$	6,029	$	4,703
Weighted-average number of common shares outstanding (denominator):
Basic	29,355,593		29,325,496
Add-incremental shares from restricted stock	77,129		39,871
Add-incremental shares from restricted stock units	3,594		1,899
Add-incremental shares from stock options	497,154		89,682
Diluted	29,933,470		29,456,948