Retirement Plans - Net periodic cost (Details) - Pension Plan - USD ($) $ in Thousands	12 Months Ended
	Feb. 29, 2020	Mar. 02, 2019	Mar. 03, 2018
Net periodic pension expense
Service cost	$ 462	$ 597	$ 1,212
Interest cost	6,186	6,159	6,340
Expected return on plan assets	(4,793)	(5,673)	(4,525)
Amortization of unrecognized net loss	1,695	1,769	3,393
Net periodic pension expense	3,550	2,852	6,420
Other changes recognized in other comprehensive loss:
Unrecognized net (gain) loss arising during period	19,046	(3,486)	(8,704)
Amortization of unrecognized net (loss) gain	(1,695)	(1,769)	(3,393)
Net amount recognized in other comprehensive loss	17,351	(5,255)	(12,097)
Net amount recognized in pension expense and other comprehensive loss	$ 20,901	$ (2,403)	$ (5,677)