Note 11 - Fair Value (Tables)

9 Months Ended

Feb. 28, 2014

Fair Value Disclosures [Abstract]

Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Valuation Techniques [Table Text Block]

	As of February 28, 2014
	Fair Value Measurements of Assets (Liabilities) Using							Carrying
	(Level 1)		(Level 2)			(Level 3)		Amount
	(in thousands of dollars)
Derivative instruments	$	-		(1,516	)		-		(1,516	)

	As of May 31, 2013
	Fair Value Measurements of Assets (Liabilities) Using								Carrying
	(Level 1)		(Level 2)			(Level 3)			Amount
	(in thousands of dollars)
Derivative instruments	$	-		(1,906	)		-			(1,906	)
Contingent consideration liability		-		-			(4,504	)		(4,504	)

Schedule of Business Acquisitions by Acquisition, Contingent Consideration [Table Text Block]

	Nine Months Ended February 28, 2014			Twelve Months Ended May 31, 2013
Balance at the beginning of the period	$	(4,504	)		-
Additions due to acquisitions		-			(4,400	)
Change in fair value		4,638			-
Accretion of fair value		(134	)		(104	)
Balance at the end of the period	$	-			(4,504	)