Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended		12 Months Ended
	Nov. 30, 2013	Nov. 30, 2012	May 31, 2013
Income Tax Contingency [Line Items]
Federal statutory corporate rate	35.00%
Estimated annualized income tax rate	(1.80%)		(4.30%)
Received income tax refunds	$ 0.4	$ 0
Income tax payments	0	0
Net deferred tax assets	6.7		6.7
Net deferred tax assets classified as current	15.4		18.8
Valuation allowances			1.5
Significant reserves for uncertain tax positions including related interest and penalties	0
Tax Years 2007 Through 2010
Income Tax Contingency [Line Items]
Adjustment following IRS review of tax returns	$ 0