Note 7 - Debt (Details Textual) $ in Thousands	1 Months Ended	6 Months Ended
May 31, 2020 USD ($)	Oct. 31, 2020 USD ($)
Line of Credit Facility, Maximum Borrowing Capacity		$ 5,000
Line of Credit Facility, Remaining Borrowing Capacity		$ 5,000
Line of Credit Facility, Interest Rate at Period End		3.65%
Notes Collateralized by Aircraft Security Agreements, Due January 2023 [Member]
Number of Notes		1
Debt Instrument, Interest Rate, Stated Percentage		6.25%
Notes Payable, Total		$ 1,427
Note Collateralized by Real Estate Due June 2024 [Member]
Number of Notes		1
Debt Instrument, Interest Rate, Stated Percentage		6.25%
Notes Payable, Total		$ 212
Note Collateralized by Equipment Due April 2022 [Member]
Number of Notes		1
Debt Instrument, Interest Rate, Stated Percentage		4.50%
Notes Payable, Total		$ 32
Note One Collateralized by Real Estate Due March 2029 [Member]
Notes Payable, Total		$ 1,347
Note One Collateralized by Real Estate Due March 2029 [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate		1.75%
Note Two Collateralized by Real Estate Due March 2029 [Member]
Notes Payable, Total		$ 617
Note Two Collateralized by Real Estate Due March 2029 [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate		1.75%
Paycheck Protection Program CARES Act [Member]
Proceeds from Issuance of Long-term Debt, Total	$ 2,001

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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

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The effective interest rate at the end of the reporting period.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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