Short-term Investments (Tables)

6 Months Ended

Mar. 31, 2015

Investments Debt And Equity Securities [Abstract]

Short-term Investments

	As of March 31, 2015 (in thousands)
	Amortized		Unrealized		Unrealized			Estimated
	Cost		Gains		Losses			Fair Value
Short-term investments:
Corporate	$	15,122	$	—	$	(5	)	$	15,117
Government		4,843		—		(2	)		4,841
Total	$	19,965	$	—	$	(7	)	$	19,958

	As of September 30, 2014 (in thousands)
	Amortized		Unrealized		Unrealized			Estimated
	Cost		Gains		Losses			Fair Value
Short-term investments:
Corporate	$	14,262	$	—	$	(27	)	$	14,235
Government		5,638		—		(12	)		5,626
Total	$	19,900	$	—	$	(39	)	$	19,861