Restatement - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended	9 Months Ended		3 Months Ended
	Feb. 28, 2013		Feb. 29, 2012	Nov. 30, 2012	Feb. 28, 2013	Feb. 29, 2012	Feb. 28, 2013 As Reported	Feb. 28, 2013 Adjustments	Nov. 30, 2012 Adjustments	Aug. 31, 2012 Adjustments
Estimated loss on contingency	$ 40,502	[1]		$ 28,300	$ 68,846		$ 68,846	$ (28,344)	$ 16,900	$ 11,400
Net income (loss)	$ (24,200)	[1]	$ 7,924		$ 41,762	$ 145,183	$ (42,192)	$ 17,992

[1] Restated