Progression of Liabilities (Detail) (USD $)	12 Months Ended
	May 31, 2012	Nov. 30, 2011
Loss Contingencies [Line Items]
Beginning Balance	$ 8,620,000
Reserves Used	(8,342,000)
Ending Balance	278,000
Product Returns
Loss Contingencies [Line Items]
Beginning Balance	4,737,000	4,737,000
Reserves Used	(3,650,000)
Changes in Estimates	(809,000)
Ending Balance	278,000	4,737,000
Recall-Related Costs
Loss Contingencies [Line Items]
Beginning Balance	3,883,000	3,883,000
Reserves Used	(4,692,000)
Changes in Estimates	809,000
Ending Balance		$ 3,883,000