Note 15 - Income Taxes - Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Accrued expenses	$ 2,155	$ 1,362
Leases	3,598	3,337
Stock-based compensation	3,356	3,325
Intangible assets	1,693	1,171
Inventories	172	169
Other assets	1,790	1,765
Net operating loss	6,647	6,513
Less valuation allowance	(9,138)	(8,248)
Total deferred tax assets	10,273	9,394
Deferred tax liabilities:
Depreciation	(32,671)	(26,750)
Goodwill	(7,858)	(5,590)
Leases	(3,598)	(3,337)
Total deferred tax liabilities	(44,127)	(35,677)
Net deferred tax liability	$ (33,854)	$ (26,283)