Net Sales by Product Category Net of Intercompany Activity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2013	Aug. 31, 2012
Segment Reporting Information [Line Items]
Net Sales	$ 27,553	$ 29,927	$ 56,273	$ 64,761
Percentage of net sales	100.00%	100.00%	100.00%	100.00%
Acoustical
Segment Reporting Information [Line Items]
Net Sales	17,942	19,360	36,363	39,283
Percentage of net sales	65.00%	65.00%	65.00%	61.00%
Coated
Segment Reporting Information [Line Items]
Net Sales	$ 9,611	$ 10,567	$ 19,910	$ 25,478
Percentage of net sales	35.00%	35.00%	35.00%	39.00%