Derivative Financial Instruments (Tables)

12 Months Ended

Sep. 30, 2021

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Notional Amounts of Outstanding Derivative Positions

The following tables summarize our outstanding foreign currency forward contracts, by currency, at September 30, 2021 and 2020: 

	September 30, 2021
	Contract Amount				Fair Value
	Foreign Currency		USD		USD
		(In thousands)
Sell foreign currency:
Euro (EUR)	EUR	17,100	$	19,829	—
Buy foreign currency:
British pound (GBP)	GBP	11,467	$	15,400	—
Singapore dollar (SGD)	SGD	6,650	$	4,900	—

	September 30, 2020
	Contract Amount				Fair Value
	Foreign Currency		USD		USD
		(In thousands)
Sell foreign currency:
Euro (EUR)	EUR	15,000	$	17,656	—
Buy foreign currency:
British pound (GBP)	GBP	16,555	$	21,300	—
Singapore dollar (SGD)	SGD	7,815	$	5,700	—

Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance

These amounts are shown below for the years ended September 30, 2021, 2020 and 2019: 

	Year Ended September 30,
	2021		2020		2019
	(In thousands)
Gain (loss) on foreign currency forward contracts	$	2,064	$	(347)	$	(896)