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Fair Value of Company's Short-Term Investment and Contingent Consideration by Valuation Hierarchy (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands | Mar. 31, 2021 | Sep. 30, 2020
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Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Total assets | $ 3,865 |
Current portion | (2,324) |
Non-current portion | (7,720) | $ (10,962)
Total liabilities | (10,044) |
Quoted Prices in Active Markets for Identical Assets (Level 1) |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Total assets | 3,865 |
Significant Unobservable (Level 3) |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Current portion | (2,324) |
Non-current portion | (7,720) | $ (10,962)
Total liabilities | (10,044) |
Corporate bonds |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Total assets | 3,865 |
Corporate bonds | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Total assets | $ 3,865 |

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