Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 01, 2012	Nov. 26, 2011	Dec. 01, 2012 Segment	Nov. 26, 2011
Segment Reporting Information [Line Items]
Number of Reportable Segments			2
Sales and operating income data
Net sales	$ 190,416	$ 174,853	$ 520,490	$ 493,748
Operating income (loss)	11,411	7,156	21,282	1,051
Architectural [Member]
Sales and operating income data
Net sales	168,770	152,087	460,015	436,516
Operating income (loss)	5,837	580	6,978	(11,597)
Large-Scale Optical [Member]
Sales and operating income data
Net sales	21,648	22,769	60,477	57,235
Operating income (loss)	6,557	7,411	17,021	15,559
Intersegment eliminations [Member]
Sales and operating income data
Net sales	(2)	(3)	(2)	(3)
Corporate and other [Member]
Sales and operating income data
Operating income (loss)	$ (983)	$ (835)	$ (2,717)	$ (2,911)