Note 6 - Pension, Postretirement and Postemployment Defined Benefit Plans (Details Textual) - USD ($)		3 Months Ended			9 Months Ended
	Dec. 27, 2020	Jun. 26, 2022	Dec. 26, 2021	Jun. 27, 2021	Jun. 26, 2022	Jun. 27, 2021	Sep. 26, 2021
Multiemployer Plans, Withdrawal Obligation		$ 24,337,020			$ 24,337,020		$ 23,471,000
Multiemployer Plans, Withdrawal Obligation, Period (Year)		20 years
Postemployment Retirement Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	$ 23,830,000		$ 1,027,000
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment	23,830,000		(6,507,000)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	$ 23,830,000		$ 1,027,000
Pension Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment		$ (0)		$ (0)	1,027,000	$ (0)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment		(0)		$ (0)	1,027,000	(0)
Defined Benefit Plan, Plan Assets, Contributions by Employer					0	$ 965,000
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		$ 0			$ 0