Gross Accounts Receivable from Significant Customers as Percentage of Total Consolidated Gross Accounts Receivable (Detail) (Accounts Receivable, Customer Concentration Risk)	Aug. 31, 2013	Feb. 28, 2013
Chrysler
Concentration Risk [Line Items]
Percentage of Consolidated Gross Accounts Receivable	18.00%	18.00%
U.S. Steel
Concentration Risk [Line Items]
Percentage of Consolidated Gross Accounts Receivable	7.00%	12.00%