Note 9 - Accounting for Share-based Compensation - Deferred Compensation Units (Details) - shares		12 Months Ended
		Nov. 28, 2020	Nov. 30, 2019	Dec. 01, 2018
Units outstanding (in shares)		562,324	509,522	475,176
Participant contributions (in shares)		31,822	33,319	23,753
Company match contributions1 (in shares)	[1]	24,414	24,837	20,812
Payouts (in shares)		(118,742)	(5,354)	(10,219)
Units outstanding (in shares)		499,818	562,324	509,522
Non Employee Directors [Member]
Units outstanding (in shares)		525,660	479,787	443,570
Participant contributions (in shares)		18,008	22,153	16,164
Company match contributions1 (in shares)	[1]	23,033	23,720	20,053
Payouts (in shares)		(111,436)	0	0
Units outstanding (in shares)		455,265	525,660	479,787
Employees [Member]
Units outstanding (in shares)		36,664	29,735	31,606
Participant contributions (in shares)		13,814	11,166	7,589
Company match contributions1 (in shares)	[1]	1,381	1,117	759
Payouts (in shares)		(7,306)	(5,354)	(10,219)
Units outstanding (in shares)		44,553	36,664	29,735

[1] The non-employee directors' company match includes 21,323, 21,504 and 18,436 deferred compensation units paid as discretionary awards to all non-employee directors in 2020, 2019 and 2018, respectively.