Revenues from External Customers and Long-Lived Assets, by Geographical Areas (Detail) - USD ($) $ in Thousands	3 Months Ended								6 Months Ended	12 Months Ended
	May 31, 2016	Feb. 29, 2016	Nov. 30, 2015	Aug. 31, 2015	May 31, 2015	Feb. 28, 2015	Nov. 30, 2014	Aug. 31, 2014	Nov. 30, 2014	May 31, 2016	May 31, 2015	May 31, 2014
Revenues:
Total revenues	$ 39,182	$ 39,498	$ 43,310	$ 53,343	$ 60,413	$ 56,342	$ 59,703	$ 61,871	$ 238,329	$ 175,333	$ 238,329	$ 241,137
Net Long Lived Assets:
Total net long-lived assets	211,914				244,791					211,914	244,791	235,010
UNITED STATES
Revenues:
Total revenues										141,535	200,323	203,806
Net Long Lived Assets:
Total net long-lived assets	168,331				197,514					168,331	197,514	188,343
Non-United States [Member]
Revenues:
Total revenues										33,798	38,006	37,331
Net Long Lived Assets:
Total net long-lived assets	$ 43,583				$ 47,277					$ 43,583	$ 47,277	$ 46,667