Elk Grove Village Asset Sale - Additional information (Detail) (USD $)	3 Months Ended			6 Months Ended	12 Months Ended		1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 29, 2012	Aug. 31, 2011	Feb. 28, 2010	Aug. 31, 2012	Feb. 28, 2013	Feb. 28, 2011	Apr. 12, 2010 Elk Grove Village	May 31, 2011 Elk Grove Village	Feb. 28, 2010 Elk Grove Village
Long Lived Assets Held-for-sale [Line Items]
Consideration received from sale of assets, gross							$ 10,000,000
Cash received from sale of assets, net				9,200,000	9,180,000	14,089,000	9,300,000
Revenue from associated business									28,600,000
Gain on sales of property plant and equipment					3,216,000	6,643,000		4,700,000
Legal fees								300,000
Employee Severance Expense	300,000	300,000	1,600,000					1,100,000
Inventory write-off expenses								$ 200,000