Note 13 - Long-term Debt (Details) - USD ($) $ in Thousands		May 31, 2016	May 31, 2015
Term Loan Facility [Member]
Long-term debt, gross		$ 641,777	$ 648,410
Long-term debt, discount	[1]	(5,210)	(7,381)
Long-term debt, deferred financing costs	[2]	(11,049)	(15,664)
Long-term debt, net		625,518	625,365
Long-term debt, discount	[1]	5,210	7,381
Notes Payable [Member]
Long-term debt, gross		400,000	400,000
Long-term debt, discount	[1]	(2,648)	(3,291)
Long-term debt, deferred financing costs	[2]	(7,223)	(8,978)
Long-term debt, net		390,129	387,731
Long-term debt, discount	[1]	2,648	3,291
Revolving Credit Facility [Member]
Long-term debt, gross
Long-term debt, discount
Long-term debt, deferred financing costs	[1]	(1,125)	(1,757)
Long-term debt, net	[2]	(1,125)	(1,757)
Long-term debt, discount
Long-term debt, gross		1,042,009	1,048,417
Long-term debt, discount	[1]	(7,858)	(10,672)
Long-term debt, deferred financing costs	[2]	(19,397)	(26,399)
Long-term debt, net		1,014,754	1,011,346
Long-term debt, discount	[1]	7,858	10,672
Capital lease agreements		232	7
Less: Current portion of long-term debt		6,806	6,640
Less: Current portion of long-term debt	[1]
Less: Current portion of long-term debt		6,806	6,640
Long-term debt, excluding current portion		1,035,203	1,041,777
Long-term debt, excluding current portion	[1]	(7,858)	(10,672)
Long-term debt, excluding current portion		$ 1,007,948	$ 1,004,706

[1] OID refers to original issue discounts on the Company's long-term debt

[2] DFC refers to deferred financing costs related to the Company's long-term debt facilities