Derivative Financial Instruments (Derivatives Not Designated as Cash Flow Hedges) (Details) - Fair Value, Inputs, Level 2 - Fair Value, Measurements, Recurring - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Jun. 30, 2021	Sep. 30, 2020
Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Foreign Currency Cash Flow Hedge Liability at Fair Value	$ 11	$ 7
Other Current Liabilities
Derivatives, Fair Value [Line Items]
Foreign Currency Cash Flow Hedge Liability at Fair Value	$ 7	$ 0