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Note A - Organization and Summary of Significant Accounting Policies (Details Textual) € in Millions, SFr in Millions |  | 1 Months Ended | 6 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Aug. 18, 2021 USD ($) | Dec. 31, 2022 USD ($) | Jun. 30, 2023 USD ($) | Jun. 30, 2024 USD ($) shares | Jun. 30, 2023 USD ($) shares | Jun. 30, 2024 EUR (€) | Jun. 30, 2024 CHF (SFr)
Income Tax Return Receivable |  |  |  | $ 3,500,000 |  |  |
Accounts Receivable, Original Amount of Settled Receivable |  | $ 3,400,000 |  |  |  |  |
Accounts Receivable, Amount Settled |  | $ 1,400,000 |  |  |  |  |
Accounts Receivable, Increase (Decrease) in Amount |  |  | $ 850,000 |  |  |  |
Asset Impairment Charges |  |  |  | 0 | $ 0 |  |
Derivative, Fixed Interest Rate | 2.40% |  |  |  |  |  |
Contract with Customer, Refund Liability |  |  |  | 0 |  |  |
Sales, Royalty and Licensing Revenue |  |  |  | 8,400,000 | 8,700,000 |  |
Royalty Expense |  |  |  | 300,000 | 300,000 |  |
Research and Development Expense |  |  |  | 1,900,000 | 2,100,000 |  |
Advertising Expense |  |  |  | $ 300,000 | $ 700,000 |  |
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration] | Secured Overnight Financing Rate (SOFR) [Member] |  |  |  |  |  |
Customer Concentration Risk [Member] | Accounts Receivable [Member] |  |  |  |  |  |  |
Number of Major Customers |  |  |  | 3 |  |  |
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Beta-alanine Raw Material [Member] |  |  |  |  |  |  |
Concentration Risk, Percentage |  |  |  | 4.40% | 21.40% |  |
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Three Customers [Member] |  |  |  |  |  |  |
Concentration Risk, Percentage |  |  |  | 72.60% | 47.40% |  |
Restricted Stock [Member] |  |  |  |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) | shares |  |  |  | 232,574 | 60,497 |  |
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] |  |  |  |  |  |  |
Derivative, Notional Amount |  |  |  | $ 11,900,000 |  |  | SFr 10.5
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member] |  |  |  |  |  |  |
Derivative, Notional Amount |  |  |  | $ 34,000,000 |  | € 30.8 |
Maximum Remaining Maturity of Foreign Currency Derivatives (Year) |  |  |  | 15 years |  |  |
Minimum [Member] |  |  |  |  |  |  |
Property, Plant and Equipment, Useful Life (Year) |  |  |  | 1 year |  | 1 year | 1 year
Maximum [Member] |  |  |  |  |  |  |
Property, Plant and Equipment, Useful Life (Year) |  |  |  | 39 years |  | 39 years | 39 years
Term Loan [Member] | Wells Fargo Bank, N.A. [Member] | Credit Agreement [Member] |  |  |  |  |  |  |
Debt Instrument, Face Amount | $ 10,000,000 |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate | 1.80% |  |  |  |  |  |
Fair Value, Inputs, Level 1 [Member] |  |  |  |  |  |  |
Fair Value, Net Asset (Liability) |  |  | 0 | $ 0 | $ 0 |  |
Fair Value, Inputs, Level 2 [Member] |  |  |  |  |  |  |
Fair Value, Net Asset (Liability) |  |  | 937,000 | 590,000 | 937,000 |  |
Fair Value, Inputs, Level 2 [Member] | Line of Credit [Member] |  |  |  |  |  |  |
Debt Instrument, Fair Value Disclosure |  |  | 0 | 3,400,000 | 0 |  |
Fair Value, Inputs, Level 2 [Member] | Term Loan [Member] |  |  |  |  |  |  |
Debt Instrument, Fair Value Disclosure |  |  | 9,500,000 | 9,200,000 | 9,500,000 |  |
Fair Value, Inputs, Level 3 [Member] |  |  |  |  |  |  |
Fair Value, Net Asset (Liability) |  |  | $ 0 | 0 | $ 0 |  |
Cost of Sales [Member] |  |  |  |  |  |  |
Income Tax Recovery |  |  |  | 2,200,000 |  |  |
Selling, General and Administrative Expenses [Member] |  |  |  |  |  |  |
Income Tax Recovery |  |  |  | $ 1,300,000 |  |  |

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