Calculation of Basic and Diluted EPS (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Aug. 31, 2013		Aug. 31, 2012
Earnings
Net income (loss) from continuing operations	$ 429		$ (7,396)
Net income from discontinued operations	0		4,738
Unvested restricted share participation	0		0
Income (Loss) allocated to common shareholders	$ 429		$ (2,658)
Shares
Weighted-average shares outstanding (in shares)	28,587		28,013
Contingently issuable shares (in shares)	5		3
Unvested restricted shares (in shares)	(14)		(18)
Basic weighted-average shares (in shares)	28,578		27,998
Stock option, restricted share and award dilution (in shares)	476		0
Diluted weighted-average shares (1) (in shares)	29,054	[1]	27,998	[1]
NET INCOME (LOSS) PER SHARE FROM CONTINUING OPERATIONS:
Basic (in USD per share)	$ 0.02		$ (0.26)
Diluted (in USD per share)	$ 0.01		$ (0.26)
NET INCOME PER SHARE FROM DISCONTINUED OPERATIONS:
Basic (in USD per share)	$ 0.00		$ 0.18
Diluted (in USD per share)	$ 0.00		$ 0.18
NET INCOME (LOSS) PER SHARE:
Basic (in USD per share)	$ 0.02		$ (0.08)
Diluted (in USD per share)	$ 0.01		$ (0.08)
Shares excluded due to antidilutive effect of stock options, restricted shares and awards (in shares)	160		1,131

[1] Shares excluded due to antidilutive effect of stock options, restricted shares and awards