Short-term Investments

3 Months Ended

Dec. 31, 2017

Investments Debt And Equity Securities [Abstract]

Short-term Investments

2.   Short-term Investments

	As of December 31, 2017 (in thousands)
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Short-term investments
Corporate bonds	$	21,739	$	—	$	(67	)	$	21,672
Government bonds		10,452		—		(39	)		10,413
Total	$	32,191	$	—	$	(106	)	$	32,085

	As of September 30, 2017 (in thousands)
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Short-term investments
Corporate bonds	$	22,829	$	—	$	(31	)	$	22,798
Government bonds		13,363		—		(24	)		13,339
Total	$	36,192	$	—	$	(55	)	$	36,137

  The Company’s short-term investments have contractual maturities ranging from January 2018 to January 2020.