Note 10 - Long-Term Debt (Details) - Interest Expense (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013	May 31, 2014
Note 10 - Long-Term Debt (Details) - Interest Expense [Line Items]
Amortization of deferred financing costs	$ 1,675	$ 1,580	$ 3,324	$ 3,136
Interest rate swaps	229	262	492	524
Revolving Facility fees and interest	216	126	358	254
Interest accreted on contingent consideration liability	679	69	800	134	134
Interest expense	22,822	22,093	45,120	44,271
Notes Payable, Other Payables [Member]
Note 10 - Long-Term Debt (Details) - Interest Expense [Line Items]
Interest expense including OID amortization	11,265	11,250	22,527	22,497
Term Loan Facility [Member]
Note 10 - Long-Term Debt (Details) - Interest Expense [Line Items]
Interest expense including OID amortization	$ 8,758	$ 8,806	$ 17,619	$ 17,726