Note 11 - Leases - Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Operating leases	$ 2,027	$ 2,112	$ 4,067	$ 4,263
Variable lease expense	574	547	1,126	1,079
Short-term operating leases	34	19	67	38
Amortization of leased assets	24	28	45	48
Interest on lease liabilities	1	29	1	57
Sublease income	(21)	(31)	(40)	(63)
Net lease cost	$ 2,639	$ 2,704	$ 5,266	$ 5,422

Amount of interest expense on finance lease liability.

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Amount of amortization expense attributable to right-of-use asset from finance lease.

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- Definition

Amount of lease cost recognized by lessee for lease contract.

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Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

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Amount of short-term lease cost, excluding expense for lease with term of one month or less.

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Amount of sublease income excluding finance and operating lease expense.

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Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

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