Derivative Financial Instruments - Company's Derivatives on Consolidated Financial Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Foreign Currency Forward Contracts | Other Income (Expense)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amount of (Loss) Gain Recognized in Income	$ (89)	$ (142)	$ 176	$ 497