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Long-Term Debt - Narrative (Details) | 1 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Jun. 30, 2017 | Sep. 30, 2017 USD ($) | Sep. 30, 2016 | Oct. 31, 2001 USD ($)
U.S. Revolver |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |
Revolving credit facility |  | $ 75,000,000 |  |
Revolving credit facility borrowings, outstanding amount |  | 0 |  |
Amount of credit facility remaining borrowing capacity |  | $ 50,900,000 |  |
Percentage of voting capital stock pledged as collateral |  | 100.00% |  |
Non-domestic subsidiaries of voting capital stock |  | 65.00% |  |
U.S. Revolver | Maximum |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |
Basis spread on variable rate |  | 1.25% |  |
U.S. Revolver | Federal Funds Rate |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |
Basis spread on variable rate |  | 0.50% |  |
U.S. Revolver | Eurocurrency Rate |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |
Basis spread on variable rate |  | 1.00% |  |
Industrial Development Revenue Bonds |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |
Borrowings |  |  |  | $ 8,000,000
Reimbursement agreement requires annual redemptions |  | $ 400,000 |  |
Interest rate |  | 1.19% |  |
The Third Amendment | U.S. Revolver |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |
Fee percentage | 0.875% |  | 1.00% |
Commitment fee percentage | 0.20% |  | 0.1875% |
Cash collateral percent of outstanding debt (at least) |  | 102.00% | 102.00% |
Consolidated current ratio (no less than) | 1.10 |  |  |
Cash collateral pledged balance |  | $ 24,900,000 |  |
Financial Standby Letter of Credit | U.S. Revolver |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |
Guarantee liability |  | $ 24,100,000 |  |

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- Definition Percentage of domestic capital stock pledged as collateral for credit facility. + References No definition available. + Details
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- Definition Amount of the total principal payments made during the annual reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -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 + Details
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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions 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://www.xbrl.org/2003/role/presentationRef -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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -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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