CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
ASC 842 transition adjustment		$ (274)				$ (274)
Balance (in shares) at May. 26, 2019			29,102
Balance at May. 26, 2019	$ 270,144		$ 29	$ 160,341	$ 109,710		$ 64
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under stock plans (in shares)			44
Issuance of stock under stock plans	0
Taxes paid by Company for employee stock plans	(55)			(55)
Stock-based compensation	528			528
Net loss	(4,784)				(4,784)
Other comprehensive income, net of tax	(612)						(612)
Balance (in shares) at Aug. 25, 2019			29,146
Balance at Aug. 25, 2019	$ 264,947		$ 29	160,814	104,652		(548)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member
Balance (in shares) at May. 31, 2020			29,224
Balance at May. 31, 2020	$ 231,044		$ 29	162,578	71,245		(2,808)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under stock plans (in shares)			18
Issuance of stock under stock plans	0
Taxes paid by Company for employee stock plans	(82)			(82)
Stock-based compensation	892			892
Net loss	(11,000)				(11,000)
Other comprehensive income, net of tax	304						304
Balance (in shares) at Aug. 30, 2020			29,242
Balance at Aug. 30, 2020	$ 221,158		$ 29	$ 163,388	$ 60,245		$ (2,504)