Income Taxes - Narrative (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	May 31, 2013
Income Tax Disclosure [Abstract]
Effective tax rate	(1.80%)	718.00%
Federal statutory tax rate	35.00%
Valuation allowance for deferred tax assets			$ 188.6
Liability for uncertain income tax positions, including accrued interest and penalties	8.0
Reduction in unrecognized tax benefits and related interest	$ 0.3
Expiration period for reduction in unrecognized tax benefits and unrelated interest	12 months