CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Aug. 30, 2020	Aug. 25, 2019
Income Statement [Abstract]
Product sales	$ 135,643	$ 138,714
Cost of product sales	119,296	123,378
Gross profit	16,347	15,336
Operating costs and expenses:
Research and development	2,508	2,821
Selling, general and administrative	17,903	16,895
Restructuring costs	8,404	0
Total operating costs and expenses	28,815	19,716
Operating loss	(12,468)	(4,380)
Dividend income	281	281
Interest income	8	25
Interest expense, net	(3,109)	(2,075)
Other expense (income), net	(21)	0
Net loss before tax	(15,309)	(6,149)
Income tax benefit	4,309	1,365
Net loss applicable to common stockholders	(11,000)	(4,784)
Net (loss) applicable to common stockholders	$ (11,000)	$ (4,784)
Net loss per common share:
Net loss per common share - basic (in dollars per share)	$ (0.38)	$ (0.16)
Net loss per common share - diluted (in dollars per share)	$ (0.38)	$ (0.16)
Shares used in per share computation:
Basic (in shares)	29,242	29,139
Diluted (in shares)	29,242	29,139
Other comprehensive income (loss), net of tax:
Net unrealized gain (losses) on interest rate swaps (net of tax effect of $(121) and $265)	$ 304	$ (612)
Other comprehensive income, net	304	(612)
Total comprehensive loss	$ (10,696)	$ (5,396)