| Note 8 - Employee Benefit Plan (Details Textual) - USD ($) | 12 Months Ended | ||
|---|---|---|---|
| Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2021 | |
| Defined Contribution Plan, Employer Discretionary Contribution Amount | $ 1,017,000 | $ 1,129,000 | $ 915,000 | 
| Employee Wages, Accrued for Monthly, Percent | 17.40% | ||
| Nestor Cables [Member] | |||
| Defined Contribution Plan, Employer Discretionary Contribution Amount | $ 1,112,000 | $ 204,000 | |
| Employee Wages, Accrued for Monthly, Percent | 18.30% | ||
| First Level of Matching [Member] | |||
| Defined Contribution Plan, Employer Matching Contribution, Percent of Match | 100.00% | ||
| Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay | 3.00% | ||
| Second Level Of Matching [Member] | |||
| Defined Contribution Plan, Employer Matching Contribution, Percent of Match | 50.00% | ||
| Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay | 3.00% | ||
| X | ||||||||||
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- Definition Employee wages accrued for monthly represented as a percentage. No definition available. 
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- Definition Amount of discretionary contributions made by an employer to a defined contribution plan. No definition available. 
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- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. No definition available. 
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- Definition Percentage employer matches of the employee's percentage contribution matched. No definition available. 
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- Details 
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- Details 
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- Details 
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