Note 15 - Changes to Stockholders' Equity - Changes Occurred in Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2019	Aug. 25, 2018	Aug. 31, 2019	Aug. 25, 2018
Balance			$ 190,309
Net income for the period	$ 2,157	$ 2,945	3,210	$ 6,321
Balance	183,946		183,946
Common Stock [Member]
Balance	52,262	53,736	52,638	53,690
Issuance of common stock	58	19	339	273
Purchase and retirement of common stock	$ (1,742)	$ (429)	$ (2,399)	$ (637)
Balance, shares (in shares)	10,452,345	10,747,122	10,527,636	10,737,950
Issuance of common stock, shares (in shares)	11,734	3,838	67,935	54,644
Purchase and retirement of common stock, shares (in shares)	(348,383)	(85,683)	(479,875)	(127,317)
Balance, shares (in shares)	10,115,696	10,665,277	10,115,696	10,665,277
Balance	$ 50,578	$ 53,326	$ 50,578	$ 53,326
Paid in Capital [Member]
Balance	0	382	0	962
Issuance of common stock	28	71	(69)	18
Purchase and retirement of common stock	(270)	(713)	(649)	(1,849)
Stock based compensation	242	260	718	869
Balance	0	0	0	0
Retained Earnings [Member]
Balance	137,127	140,934	140,009	139,378
Purchase and retirement of common stock	(2,487)	(1,036)	(3,798)	(1,036)
Cumulative effect of a change in accounting principal	0	0	(21)	0
Reclassification of certain tax effects from accumulated other comprehensive loss	0	0	0	545
Net income for the period	2,157	2,945	3,210	6,321
Cash dividends	(1,264)	(1,338)	(3,867)	(3,703)
Balance	135,533	141,505	135,533	141,505
AOCI Attributable to Parent [Member]
Balance	(2,223)	(2,956)	(2,338)	(2,570)
Reclassification of certain tax effects from accumulated other comprehensive loss	0	0	0	(545)
Amortization of pension costs, net of tax	58	80	173	239
Balance	$ (2,165)	$ (2,876)	$ (2,165)	$ (2,876)