Note 9 - Leases - Lease Expense (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 28, 2020	Mar. 30, 2019
Operating leases	[1]	$ 2,151	$ 2,122
Variable lease expense		532	566
Short-term operating leases		19	78
Amortization of leased assets		20	41
Interest on lease liabilities		28	59
Sublease income		(32)	(36)
Net lease cost		$ 2,718	$ 2,830

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