Note 9 - Long-Term Debt (Details) - Interest Expense (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013	May 31, 2013
Note 9 - Long-Term Debt (Details) - Interest Expense [Line Items]
Amortization of deferred financing costs	$ 1,577	$ 1,210	$ 4,713	$ 3,600
Interest rate swaps	246	247	766	772
Revolving Facility fees and interest	125	160	379	612
Interest accreted on contingent liability			134		104
Other interest		2	6	5
Total interest expense	21,900	21,952	66,172	68,691
Notes Payable, Other Payables [Member]
Note 9 - Long-Term Debt (Details) - Interest Expense [Line Items]
Interest expense including OID amortization	11,250	11,236	33,747	33,705
Term Loan [Member]
Note 9 - Long-Term Debt (Details) - Interest Expense [Line Items]
Interest expense including OID amortization	$ 8,702	$ 9,097	$ 26,427	$ 29,997