Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Sep. 30, 2019 |
Sep. 30, 2018 |
|
| Valuation And Qualifying Accounts Disclosure [Line Items] | ||
| Balance at Beginning of Period | $ 1,453 | |
| Balance at Beginning of Period | 30,551 | |
| Charged to Costs and Expenses, net of Recoveries | 436 | $ 1,009 |
| Balance at End of Period | 951 | 1,453 |
| Balance at End of Period | 32,050 | 30,551 |
| Inventory Obsolescence Reserve | ||
| Valuation And Qualifying Accounts Disclosure [Line Items] | ||
| Balance at Beginning of Period | 30,551 | 29,614 |
| Charged to Costs and Expenses | 4,614 | 4,353 |
| (Deductions) and Additions | (3,115) | (3,416) |
| Balance at End of Period | 32,050 | 30,551 |
| Allowance for Doubtful Accounts on Accounts and Financing Receivables | ||
| Valuation And Qualifying Accounts Disclosure [Line Items] | ||
| Balance at Beginning of Period | 3,302 | 2,415 |
| Charged to Costs and Expenses, net of Recoveries | 436 | 1,009 |
| (Deductions) and Additions | (2,787) | (122) |
| Balance at End of Period | $ 951 | $ 3,302 |