Note 9 - Long-term Debt - Long-term Debt (Details) - USD ($) $ in Thousands		Feb. 28, 2017	May 31, 2016
Long-term debt, gross		$ 1,056,887	$ 1,042,009
Long-term debt, discount	[1]	(5,625)	(7,858)
Long-term debt, deferred financing costs	[2]	(14,117)	(19,397)
Long-term debt, net		1,037,145	1,014,754
Capital lease agreements		85	232
Less: Current portion of long-term debt		26,718	6,806
Less: Current portion of long-term debt		26,718	6,806
Long-term debt, excluding current portion		1,030,169	1,035,203
Long-term debt, excluding current portion	[1]	(5,625)	(7,858)
Long-term debt, excluding current portion		1,010,427	1,007,948
Revolving Credit Facility [Member]
Long-term debt, gross		20,000
Long-term debt, net		20,000
Term Loan Facility [Member]
Long-term debt, gross		636,802	641,777
Long-term debt, discount	[1]	(3,505)	(5,210)
Long-term debt, deferred financing costs	[2]	(8,333)	(12,174)
Long-term debt, net		624,964	624,393
Notes Payable [Member]
Long-term debt, gross		400,000	400,000
Long-term debt, discount	[1]	(2,120)	(2,648)
Long-term debt, deferred financing costs	[2]	(5,784)	(7,223)
Long-term debt, net		$ 392,096	$ 390,129

[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