Note 11 - Leases - Lease Expense (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 26, 2020	Dec. 28, 2019
Operating leases (1)	[1]	$ 8,374	$ 8,525
Variable lease expense		2,110	2,318
Short-term operating leases		93	256
Amortization of leased assets		84	102
Interest on lease liabilities		57	146
Sublease income		(113)	(133)
Net lease cost		$ 10,605	$ 11,214

[1] Operating lease cost excludes impairment expense of $0.2 million related to the write-down of the Fontana facility right-of-use asset recognized in 2019.