Note 8 - Accounting for Share-based Compensation - Deferred Compensation Units (Details)	9 Months Ended
	Sep. 01, 2018 shares
Units outstanding (in shares)	475,176
Participant contributions (in shares)	18,012
Company match contributions (in shares)	20,237
Payouts (in shares)	(6,090)
Units outstanding (in shares)	507,335
Non Employee Directors [Member]
Units outstanding (in shares)	443,570
Participant contributions (in shares)	11,738
Company match contributions (in shares)	19,610
Payouts (in shares)
Units outstanding (in shares)	474,918
Employees [Member]
Units outstanding (in shares)	31,606
Participant contributions (in shares)	6,274
Company match contributions (in shares)	627
Payouts (in shares)	(6,090)
Units outstanding (in shares)	32,417