Note 12 - Fair Value (Tables)

3 Months Ended

Aug. 31, 2015

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	As of August 31, 2015
	Fair Value Measurements of Assets (Liabilities) Using								Carrying
	(Level 1)		(Level 2)			(Level 3)			Amount
	(in thousands of dollars)
Derivative instruments	$	-		(506	)		-			(506	)
Contingent consideration liability	$	-		-			(18,863	)		(18,863	)

	As of May 31, 2015
	Fair Value Measurements of Assets (Liabilities) Using								Carrying
	(Level 1)		(Level 2)			(Level 3)			Amount
	(in thousands of dollars)
Derivative instruments	$	-		(686	)		-			(686	)
Contingent consideration liability	$	-		-			(18,596	)		(18,596	)

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

	Three Months Ended			Twelve Months Ended
	August 31, 2015			May 31, 2015
Balance at the beginning of the period	$	(18,596	)		(11,300	)
Additions due to acquisitions		-			(6,469	)
Payments		18			87
Accretion of fair value		(285	)		(914	)
Balance at the end of the period	$	(18,863	)		(18,596	)