Derivative Financial Instruments (Tables)

9 Months Ended

Jun. 30, 2017

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Summary of Outstanding Foreign Currency Forward Contracts

The following tables summarize our outstanding foreign currency forward contracts, by currency, at June 30, 2017 and September 30, 2016:

	June 30, 2017
	Contract Amount				Fair Value
	Foreign Currency		US$		US$
	(In thousands)
Sell foreign currency:
Euro (EUR)	EUR	4,250	$	4,886	$	—
Buy foreign currency:
British pound (GBP)	GBP	5,451	$	7,100	$	—

	September 30, 2016
	Contract Amount				Fair Value
	Foreign Currency		US$		US$
	(In thousands)
Sell foreign currency:
Euro (EUR)	EUR	7,850	$	8,743	$	—
Buy foreign currency:
British pound (GBP)	GBP	7,721	$	10,000	$	—

Losses on Derivative Financial Instruments

Losses on derivative financial instruments are recorded in our condensed consolidated statements of income and comprehensive income as a component of other income, net, and consisted of the following: 

	Quarter Ended June 30,				Nine Months Ended June 30,
	2017		2016		2017		2016
	(In thousands)
Losses on foreign currency forward contracts	$	—	$	1,018	$	505	$	2,273