Investments (Tables)

3 Months Ended

Dec. 31, 2017

Investments, Debt and Equity Securities [Abstract]

Summary of Investments by Type of Security

The following tables summarizes investments by type of security as of December 31, 2017 and September 30, 2017, respectively (amounts shown in thousands):

December 31, 2017:	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Available-for-sale securities:
U.S. Treasury, short-term	$	7,356	$	—	$	(16	)	$	7,340
Corporate debt securities, short-term	24,689		—		(30		)	24,659
U.S. Treasury, long-term	3,678		—		(13		)	3,665
Corporate debt securities, long-term	3,830		—		(13		)	3,817
Total	$	39,553	$	—	$	(72	)	$	39,481

September 30, 2017:	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Available-for-sale securities:
U.S. Treasury, short-term	$	3,897	$	—	$	(3	)	$	3,894
Corporate debt securities, short-term	26,393		—		(8		)	26,385
Corporate debt securities, long-term	3,785		—		(5		)	3,780
Total	$	34,075	$	—	$	(16	)	$	34,059

Summary of Fair Value of Investments Measured on Recurring Basis

The following tables represent the fair value hierarchy of the Company’s investments and acquisition-related contingent consideration as of December 31, 2017 and September 30, 2017, respectively (amounts shown in thousands):

	Balance		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
December 31, 2017:
Assets:
Short-term investments:
U.S. Treasury	$	7,340	$	7,340	$	—	$	—
Corporate debt securities
Financial	4,890		—		4,890		—
Industrial	9,918		—		9,918		—
Commercial paper
Financial	8,855		—		8,855		—
Industrial	996		—		996		—
Total short-term investments at fair value	31,999		7,340		24,659		—
Long-term investments:
U.S. Treasury	3,665		3,665		—		—
Corporate debt securities
Financial	1,902		—		1,902		—
Industrial	1,915		—		1,915		—
Total assets at fair value	$	39,481	$	11,005	$	28,476	$	—
Liabilities:
Acquisition-related contingent consideration	3,120		—		—		3,120
Total liabilities at fair value	$	3,120	$	—	$	—	$	3,120

	Balance		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
September 30, 2017:
Assets:
Short-term investments:
U.S. Treasury	$	3,894	$	3,894	$	—	$	—
Corporate debt securities
Financial	3,041		—		3,041		—
Industrial	9,503		—		9,503		—
Commercial paper
Financial	10,850		—		10,850		—
Industrial	2,991		—		2,991		—
Total short-term investments at fair value	30,279		3,894		26,385		—
Long-term investments:
Corporate debt securities
Financial	1,858		—		1,858		—
Industrial	1,922		—		1,922		—
Total assets at fair value	$	34,059	$	3,894	$	30,165	$	—
Liabilities:
Acquisition-related contingent consideration	354		—		—		354
Total liabilities at fair value	$	354	$	—	$	—	$	354

Summary of Contingent Consideration Measured at Fair Value

The following table includes a summary of the contingent consideration measured at fair value using significant unobservable inputs (Level 3) during the three months ended December 31, 2017(amounts shown in thousands):

Balance at September 30, 2017	$	354
Issuance of contingent consideration	2,867
Expenses recorded due to changes in fair value	609
Issuance of common stock	(710		)
Balance at December 31, 2017	$	3,120