Interest and Foreign Exchange (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Aug. 31, 2017	May 31, 2017	Feb. 28, 2017	Nov. 30, 2016	Aug. 31, 2016	May 31, 2016	Feb. 28, 2016	Nov. 30, 2015	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Interest Expense [Line Items]
Interest and other expense									$ 23,519	$ 17,268	$ 18,975
Foreign exchange (gain) loss									673	(3,766)	(7,796)
Interest and foreign exchange	$ 8,901	$ 7,894	$ 5,673	$ 1,724	$ 2,937	$ 3,712	$ 1,417	$ 5,436	$ 24,192	$ 13,502	$ 11,179