Note 7 - Notes Payable (Details Textual) - USD ($)		3 Months Ended
Feb. 28, 2018	Mar. 31, 2020	Mar. 31, 2019
Interest Expense, Total		$ 1,142	$ 1,128
Senior Notes [Member]
Proceeds from Notes Payable, Total	$ 50,000
Debt Instrument, Interest Rate, Stated Percentage	5.00%
Long-Term Debt, Maturity, Remainder of Fiscal Year		8,964
Long-Term Debt, Maturity, Year Two		12,487
Long-Term Debt, Maturity, Year Three		13,126
Long-Term Debt, Maturity, Year Four		2,252
Interest Expense, Total		$ 485	$ 621

Contractual interest rate for funds borrowed, under the debt agreement.

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