Note L - Revision to Prior Period Financial Statements - Effect of Revision on Specific Line Items on Previously Issued Unaudited Financial Statements (Details) - USD ($)	Jul. 04, 2021	Apr. 04, 2021	Dec. 31, 2020	Jun. 28, 2020
Right-of-Use Lease Assets	$ 10,409,000	$ 10,653,000	$ 3,363,000
Total Assets	406,535,000	402,661,000	433,170,000	$ 406,320,000
Lease Liabilities – Non-Current	9,877,000	10,072,000	2,790,000
Total Liabilities	56,845,000	62,542,000	58,822,000
Total Liabilities and Stockholders’ Equity	$ 406,535,000	402,661,000	$ 433,170,000
Previously Reported [Member]
Right-of-Use Lease Assets		3,223,000
Total Assets		395,231,000
Lease Liabilities – Non-Current		2,642,000
Total Liabilities		55,112,000
Total Liabilities and Stockholders’ Equity		395,231,000
Revision of Prior Period, Error Correction, Adjustment [Member]
Right-of-Use Lease Assets		7,430,000
Total Assets		7,430,000
Lease Liabilities – Non-Current		7,430,000
Total Liabilities		7,430,000
Total Liabilities and Stockholders’ Equity		$ 7,430,000