Note 9 - Accounting for Share-Based Compensation - Deferred Compensation Units (Details) - shares		12 Months Ended
		Nov. 30, 2019	Dec. 01, 2018	Dec. 02, 2017
Units outstanding (in shares)		509,522	475,176	465,435
Participant contributions (in shares)		33,319	23,753	21,618
Company match contributions (in shares)	[1]	24,837	20,812	17,900
Payouts (in shares)		(5,354)	(10,219)	(29,777)
Units outstanding (in shares)		562,324	509,522	475,176
Non Employee Directors [Member]
Units outstanding (in shares)		479,787	443,570	424,319
Participant contributions (in shares)		22,153	16,164	16,051
Company match contributions (in shares)	[1]	23,720	20,053	17,343
Payouts (in shares)		0	0	(14,143)
Units outstanding (in shares)		525,660	479,787	443,570
Employees [Member]
Units outstanding (in shares)		29,735	31,606	41,116
Participant contributions (in shares)		11,166	7,589	5,567
Company match contributions (in shares)	[1]	1,117	759	557
Payouts (in shares)		(5,354)	(10,219)	(15,634)
Units outstanding (in shares)		36,664	29,735	31,606

[1] The non-employee directors' company match includes 21,504 and 18,436 and 15,738 deferred compensation units paid as discretionary awards to all non-employee directors in 2019, 2018 and 2017, respectively.