Summary of Significant Accounting Policies Shares Excluded from Calculation as Effect of Conversion into Shares of Common Stock (Parenthetical) (Detail) (Details) (Series A preferred stock)	6 Months Ended
	Aug. 31, 2013	Aug. 31, 2012
Series A preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Series A convertible preferred stock, dividend rate	6.25%	6.25%