Cash Equivalents and Short-term Investments (Tables)

12 Months Ended

Jan. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Schedule of Amortized Costs, Unrealized Gains and Losses and Estimated Fair Value of Cash Equivalents and Short-term Investments

The amortized costs, unrealized gains and losses and estimated fair values of the Company’s cash equivalents and short-term investments as of January 31, 2018 and 2017 were as follows (in thousands):

	As of January 31, 2018
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Cash equivalents:
Money market funds	$	90,770	$	—	$	—		$	90,770
Total cash equivalents	$	90,770	$	—	$	—		$	90,770
Short-term investments:
Commercial paper	$	15,946	$	—	$	—		$	15,946
U.S. treasury securities	61,896		—		(158		)	61,738
Corporate debt securities	24,125		—		(44		)	24,081
Total short-term investments	101,967		—		(202		)	101,765
Total	$	192,737	$	—	$	(202	)	$	192,535

	As of January 31, 2017
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Cash equivalents:
Money market funds	$	10,565	$	—	$	—		$	10,565
Total cash equivalents	$	10,565	$	—	$	—		$	10,565
Short-term investments:
Asset-backed securities	$	1,538	$	—	$	—		$	1,538
Corporate debt securities	12,842		13		(3		)	12,852
Total short-term investments	14,380		13		(3		)	14,390
Total	$	24,945	$	13	$	(3	)	$	24,955

Schedule of Contractual Maturities of Short-term Investments

The following tables present the contractual maturities of the Company’s short-term investments as of January 31, 2018 and 2017 (in thousands):

	As of January 31, 2018				As of January 31, 2017
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Due within one year	$	93,421	$	93,237	$	12,842	$	12,852
Due between one to five years	8,546		8,528		1,538		1,538
	$	101,967	$	101,765	$	14,380	$	14,390