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Note 1 - Nature of the Business and Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2020
Payment, Tax Withholding, Share-based Payment Arrangement		$ 2,568	$ 1,295	$ 256
Treasury Stock, Value, Ending Balance		256	256
Contract with Customer, Asset, after Allowance for Credit Loss, Total		0	0
Advertising Expense		38,500	34,300	29,400
Prepaid Advertising		100	600	300
Cost of Goods and Services Sold, Total		185,880	131,665	103,247
Research and Development Expense, Total		800	1,200	500
Shipping and Handling [Member]
Cost of Goods and Services Sold, Total		27,200	19,800	$ 15,900
Draw Term Loan [Member] \| Interest Expense [Member]
Amortization of Debt Issuance Costs	$ 600
Credit Facility [Member]
Amortization of Debt Issuance Costs		800
Debt Issuance Costs, Net, Total		1,200
Credit Facility [Member] \| Other Assets [Member]
Debt Issuance Costs, Net, Total		900
Credit Facility [Member] \| Other Current Assets [Member]
Debt Issuance Costs, Net, Total		$ 300
Credit Facility [Member] \| Draw Term Loan [Member]
Debt Issuance Costs, Net, Total	$ 100		$ 600		$ 600
Credit Facility [Member] \| Revolving Credit Facility [Member]
Debt Issuance Costs, Net, Total					$ 800
Furniture and Fixtures [Member]
Property, Plant and Equipment, Useful Life (Year)		7 years
Transportation Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)		5 years
Refrigeration Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)		9 years
Machinery and Equipment [Member] \| Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)		5 years
Machinery and Equipment [Member] \| Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)		10 years
Building and Building Improvements [Member] \| Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)		15 years
Building and Building Improvements [Member] \| Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)		39 years
Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation (in shares)		32,611	32,096	14,169
Payment, Tax Withholding, Share-based Payment Arrangement		$ 2,600	$ 1,300	$ 300