Note 12 - Fair Value (Details) - Contingent Consideration Liability (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended		12 Months Ended
	Feb. 28, 2015	Feb. 28, 2015	Feb. 28, 2014	May 31, 2014
Contingent Consideration Liability [Abstract]
Balance at the beginning of the period		$ (11,300)	$ (4,504)	$ (4,504)
Additions due to acquisitions		(6,456)		(11,300)
Change in fair value		0	(4,638)	4,638
Payments		56
Accretion of fair value	158	(642)	(140)	(134)
Balance at the end of the period	$ (18,342)	$ (18,342)		$ (11,300)