Note 10 - Derivative Financial Instruments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Aug. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative, Amount of Hedged Item (in Dollars)	$ 320.0
Derivative, Lower Fixed Interest Rate Range	1.25%
Derivative, Average Fixed Interest Rate	1.59%
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred (in Dollars)	$ 1.0