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Long-Term Debt - Additional Information (Details) - USD ($) |  |  |  | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | ---
Nov. 22, 2019 | Nov. 08, 2018 | Mar. 02, 2011 | Sep. 30, 2019 | Mar. 31, 2019 | Sep. 30, 2018
Second Amendment |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Unencumbered liquid asset value |  |  | $ 10,000,000 |  |  |
Fourth Amendment |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Unencumbered liquid asset value |  |  |  |  | $ 5,000,000 |
Minimum tangible net worth |  |  |  |  | $ 140,000,000 |
Fourth Amendment | Subsequent Event |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Unencumbered liquid asset value | $ 5,000,000 |  |  |  |  |
Minimum tangible net worth | 140,000,000 |  |  |  |  |
Fifth Amendment | Subsequent Event |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Unencumbered liquid asset value | 10,000,000 |  |  |  |  |
Minimum tangible net worth | $ 145,000,000 |  |  |  |  |
Frost Bank Credit Agreement |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Total long-term debt outstanding |  |  |  | $ 0 |  | $ 0
Line of credit borrowing capacity |  |  | $ 30,000,000 |  |  |
Credit agreement borrowing availability |  |  |  | $ 27,000,000 |  |
Frost Bank Credit Agreement | Second Amendment |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Credit agreement expiration date |  |  | 2019-04 |  |  |
Frost Bank Credit Agreement | Third Amendment |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Credit agreement expiration date |  | 2020-04 |  |  |  |
Frost Bank Credit Agreement | Fifth Amendment | Subsequent Event |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Credit agreement expiration date | 2022-04 |  |  |  |  |
Frost Bank Credit Agreement | Prime Rate |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Marginal interest rate |  |  |  | 5.00% |  |
Frost Bank Credit Agreement | Certain Accounts Receivable | Second Amendment |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Borrowing base as percentage of assets |  |  | 80.00% |  |  |
Frost Bank Credit Agreement | New Agreement |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Credit agreement date |  |  |  | Mar. 02, 2011 |  |
Frost Bank Credit Agreement | New Agreement | Subsequent Event |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Credit agreement date | Nov. 30, 2019 |  |  |  |  |
Frost Bank Credit Agreement | Certain Notes Receivable | Second Amendment |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Borrowing base as percentage of assets |  |  | 50.00% |  |  |
Maximum amount of borrowing based upon assets |  |  | $ 10,000,000 |  |  |
Frost Bank Credit Agreement | Certain Inventories | Second Amendment |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Borrowing base as percentage of assets |  |  | 25.00% |  |  |
Maximum amount of borrowing based upon assets |  |  | $ 20,000,000 |  |  |

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- Definition Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition The carrying value as of the balance sheet date of the noncurrent portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=99376301&loc=d3e1336-112600 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 45 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=99376301&loc=d3e1314-112600 + Details
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