Component of Interest and Foreign Exchange (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Aug. 31, 2012	May 31, 2012	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2011	May 31, 2011	Feb. 28, 2011	Nov. 30, 2010	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2010
Interest Expense [Line Items]
Interest and other expense									$ 22,474	$ 30,155	$ 36,214
Accretion of term loan debt discount										3,564	4,377
Accretion of convertible debt discount									3,259	3,021	3,771
Foreign exchange (gain) loss									(924)	252	842
Interest and foreign exchange	$ 6,236	$ 6,560	$ 6,630	$ 5,383	$ 6,345	$ 9,807	$ 10,536	$ 10,304	$ 24,809	$ 36,992	$ 45,204