Fair Value of Financial Instruments (Tables)

12 Months Ended

Sep. 30, 2018

Fair Value Disclosures [Abstract]

Fair Value of Company's Short-term Investments, Contingent Earn-Out Liability and Foreign Currency Forward Contracts

The following tables present the fair value of the Company’s short-term investments, contingent earn-out liability and foreign currency forward contracts by valuation hierarchy and input (in thousands):

	AS OF SEPTEMBER 30, 2018
	Quoted Prices in Active Markets for IdenticalAssets (Level 1)		SignificantOther Observable (Level 2)			Significant Unobservable (Level 3)			Totals
Short-term investments
Corporate bonds	$	17,791	$	—		$	—		$	17,791
Government bonds		7,680		—			—			7,680
Contingent earn-out liability		—		—			(7,713	)		(7,713	)
Foreign currency forward contract		—		(270	)		—			(270	)
Total	$	25,471	$	(270	)	$	(7,713	)	$	17,488

	AS OF SEPTEMBER 30, 2017
	Quoted Prices in Active Markets for IdenticalAssets (Level 1)		Significant Other Observable (Level 2)		Significant Unobservable (Level 3)		Totals
Short-term investments
Corporate bonds	$	22,798	$	—	$	—	$	22,798
Government bonds		13,339		—		—		13,339
Total	$	36,137	$	—	$	—	$	36,137