Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Nov. 30, 2019	Dec. 01, 2018	Nov. 30, 2019	Dec. 01, 2018
Sales and operating income data
Net sales	$ 337,916	$ 357,718	$ 1,050,340	$ 1,056,382
Operating income (loss)	21,594	31,408	72,210	82,062
Architectural Framing Systems
Sales and operating income data
Net sales	165,517	181,306	533,432	550,193
Operating income (loss)	6,345	12,903	34,141	43,554
Architectural Glass
Sales and operating income data
Net sales	89,433	98,524	288,862	263,533
Operating income (loss)	4,092	5,851	16,951	9,168
Architectural Services
Sales and operating income data
Net sales	69,043	72,828	195,787	220,051
Operating income (loss)	6,533	8,659	15,082	21,435
Large-Scale Optical
Sales and operating income data
Net sales	24,405	23,377	66,449	64,522
Operating income (loss)	6,754	6,628	15,561	15,845
Intersegment eliminations
Sales and operating income data
Net sales	(10,482)	(18,317)	(34,190)	(41,917)
Corporate and other
Sales and operating income data
Operating income (loss)	$ (2,130)	$ (2,633)	$ (9,525)	$ (7,940)