Note 10 - Derivative Financial Instruments (Details) - The Loss From Accumulated Other Comprehensive Income (Loss) (“OCI”) Into Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Losses on cash flow hedges:
Interest expense	$ 22,093	$ 22,251	$ 44,271	$ 46,739
Effective Portion [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Losses on cash flow hedges:
Interest expense	(246)	(252)	(503)	(518)
Ineffective Portion [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Losses on cash flow hedges:
Interest expense	$ (10)	$ (4)	$ (7)	$ (7)