Note 6 - Employee Benefit Plans - Post-retirement Benefit Obligation to Funded Status and Liability (Details) - Postretirement Health Coverage [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017
Accumulated benefit obligation at beginning of year	$ 3,148	$ 2,490
Interest cost	105	95
Actuarial (gain) loss	(216)	677
Benefits paid	(157)	(114)
Accumulated benefit obligation at end of year	2,880	3,148
Plan assets at end of year
Funded status	$ (2,880)	$ (3,148)