Note 11 - Commitments (Details Textual)		12 Months Ended
	Oct. 03, 2016 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Apr. 20, 2018 USD ($)
Variable Expenses Gallon		$ 52,000	$ 49,000
Selling, General and Administrative Expenses [Member]
Operating Lease, Expense		$ 35,000
Facility in Garden City, Kansas [Member]
Lessee, Operating Lease, Term of Contract		21 years
Number of Renewals		1
Operating Leases, Monthly Rent Expense		$ 2,187
Fuel Flowage Fee, Per Gallon		0.06
Additional Facilities in Garden City Kansas [Member]
Lessee, Operating Lease, Term of Contract	14 years
Operating Leases, Monthly Rent Expense	$ 565
Truck Lease [Member]
Lessee, Finance Lease, Term of Contract				5 years
Capital Lease, Lessee, Purchase Price of Capital Leased Asset				$ 1
Truck Lease [Member] | London Interbank Offered Rate (LIBOR) [Member]
Capital Leases of Lessee, Contingent Rentals, Basis Spread on Variable Rate				4.16%