Short-term Investments

6 Months Ended

Mar. 31, 2017

Investments Debt And Equity Securities [Abstract]

Short-term Investments

2.   Short-term Investments

	As of March 31, 2017 (in thousands)
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Short-term investments
Corporate bonds	$	18,767	$	—	$	(44	)	$	18,723
Government bonds		10,165		—		(26	)		10,139
Total	$	28,932	$	—	$	(70	)	$	28,862

	As of September 30, 2016 (in thousands)
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Short-term investments
Corporate bonds	$	17,342	$	—	$	(19	)	$	17,323
Government bonds		10,169		—		(1	)		10,168
Total	$	27,511	$	—	$	(20	)	$	27,491