Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Nov. 30, 2013	Dec. 01, 2012	Nov. 30, 2013	Dec. 01, 2012
Sales and operating income data
Net sales	$ 199,430	$ 190,416	$ 557,028	$ 520,490
Operating income (loss)	12,707	11,411	28,180	21,282
Architectural Glass [Member]
Sales and operating income data
Net sales	73,365	74,921	218,142	197,264
Operating income (loss)	1,641	461	3,782	(3,963)
Architectural Services segment [Member]
Sales and operating income data
Net sales	51,167	49,125	139,820	134,696
Operating income (loss)	351	(196)	(1,401)	(3,794)
Architectural Framing Systems Segment [Member]
Sales and operating income data
Net sales	58,981	51,605	152,877	146,182
Operating income (loss)	5,782	5,573	13,026	14,735
Large-Scale Optical [Member]
Sales and operating income data
Net sales	22,699	21,648	61,917	60,477
Operating income (loss)	6,058	6,557	16,072	17,021
Intersegment eliminations [Member]
Sales and operating income data
Net sales	(6,782)	(6,883)	(15,728)	(18,129)
Corporate and other [Member]
Sales and operating income data
Operating income (loss)	$ (1,125)	$ (984)	$ (3,299)	$ (2,717)