Note 8 - Leases - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Amortization of right-of-use assets	$ 413	$ 422	$ 435
Interest on lease liabilities	90	79	57
Operating lease cost	4,627	3,647	1,934
Short-term lease cost	993	745	1,442
Variable lease cost	158	199	141
Total lease cost	$ 6,281	$ 5,092	$ 4,009

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

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