Derivative Instruments (Tables)

12 Months Ended

Sep. 30, 2017

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Net Gains and Losses Realized on Derivative Instruments

Net gains and losses related to these contracts are recorded as a component of "Other (expense) income, net" in the accompanying Consolidated Statements of Operations and are as follows for the fiscal years ended September 30, 2017, 2016 and 2015 (in thousands):

	Fiscal Year Ended September 30,
	2017		2016		2015
Realized (losses) gains on derivatives not designated as hedging instruments	$	(545)	$	1,434	$	628

Notional Amounts Outstanding under Foreign Currency Contracts

The Company had the following notional amounts outstanding under foreign currency contracts that do not qualify for hedge accounting at September 30, 2017 and 2016 (in thousands):

September 30, 2017:
	Notional Amount			Notional Amount	Fair Value of		Fair Value of
Buy Currency	of Buy Currency	Sell Currency	Maturity	of Sell Currency	Assets		Liabilities
Japanese Yen	391,500	U.S. Dollar	October 2017	3,473	$	1	$	—
U.S. Dollar	1,074	British Pound	October 2017	800		1		—
Korean Won	3,230,100	U.S. Dollar	October 2017	2,833		—		(8)
U.S. Dollar	6,294	Chinese Yuan	October 2017	41,800		—		(2)
Euro	13,700	U.S. Dollar	October 2017	16,167		—		(62)
British Pound	188	Norwegian Krone	October 2017	2,000		—		—
Singapore Dollar	700	U.S. Dollar	October 2017	515		—		—
U.S. Dollar	226	Israeli Shekel	October 2017	800		—		—
U.S. Dollar	3,600	Swiss Franc	October 2017	3,500		2		—
Euro	19,200	British Pound	October 2017	16,888		—		(74)
					$	4	$	(146)

September 30, 2016:
	Notional Amount			Notional Amount	Fair Value of		Fair Value of
Buy Currency	of Buy Currency	Sell Currency	Maturity	of Sell Currency	Assets		Liabilities
British Pound	190	Swedish Krona	October 2016	2,100	$	1	$	—
Japanese Yen	124,000	U.S. Dollar	October 2016	1,229		—		—
U.S. Dollar	6,107	British Pound	October 2016	4,710		2		—
Euro	13,300	U.S. Dollar	October 2016	14,976		—		(40)
U.S. Dollar	5,815	Chinese Yuan	October 2016	39,000		—		(33)
Korean Won	2,488,000	U.S. Dollar	October 2016	2,255		1		—
Euro	7,482	British Pound	October 2016	6,500		—		(23)
U.S. Dollar	311	Israeli Shekel	October 2016	1,169		1		—
Singapore Dollar	360	U.S. Dollar	October 2016	265		—		—
U.S. Dollar	210	Taiwanese Dollar	October 2016	6,600		—		—
British Pound	171	Norwegian Krone	October 2016	1,800		—		—
					$	5	$	(96)