Note 11 - Fair Value (Tables)

3 Months Ended

Aug. 31, 2013

Fair Value Disclosures [Abstract]

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

	As of August 31, 2013
	Fair Value Measurements of Assets (Liabilities) Using							Carrying
	(Level 1)	(Level 2)			(Level 3)			Amount
		(in thousands of dollars)
Derivative instruments		$	(1,367	)					(1,367	)
Contingent consideration liability					$	(3,251	)		(3,251	)

	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]

	Three Months Ended August 31, 2013			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		1,320			-
Accretion of fair value		(67	)		(104	)
Balance at the end of the period	$	(3,251	)		(4,504	)