Note 3 - Consolidated Variable Interest Entity (Details Textual) - USD ($) $ in Thousands	Feb. 29, 2016	Nov. 30, 2016	May 31, 2016	May 31, 2015
Goodwill		$ 854,416	$ 857,023	$ 842,258
Business Combination, Contingent Consideration, Liability		$ 42,344	$ 40,356	$ 18,596
Sentilus [Member]
Payments to Acquire Businesses, Gross	$ 6,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	1,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Equipment	500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	18,800
Goodwill	100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent	7,200
Business Combination, Contingent Consideration, Liability	$ 7,200