Note 8 - Deferred Revenue (Details) - Deferred Financing Costs (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2013	Aug. 31, 2012
Deferred Revenue Arrangement [Line Items]
Balance at beginning of period	$ 39,449	$ 38,769
Debt issuance costs		11,412
Loss on extinguishment of debt		(6,686)
Amortization	(1,556)	(5,107)
Balance at end of period	37,893	39,449
Deferred Financing Costs [Member]
Deferred Revenue Arrangement [Line Items]
Loss on extinguishment of debt		$ (5,625)