Cash Equivalents and Short-Term Investments (Tables)

3 Months Ended

Apr. 30, 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 cost, unrealized gain (loss) and estimated fair value of the Company’s cash equivalents and short-term investments as of April 30, 2018 and January 31, 2018 were as follows (in thousands):

	As of April 30, 2018
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(unaudited)
Cash equivalents:
Money market funds	$	145,932	$	—	$	—		$	145,932
Commercial paper	9,972		—		—			9,972
U.S. treasury securities	9,995		—		—			9,995
Corporate debt securities	6,996		—		(1		)	6,995
Total cash equivalents	$	172,895	$	—	$	(1	)	$	172,894
Short-term investments:
Commercial paper	$	43,639	$	—	$	—		$	43,639
U.S. treasury securities	251,000		—		(270		)	250,730
Corporate debt securities	40,972		1		(57		)	40,916
Total short-term investments	335,611		1		(327		)	335,285
Total	$	508,506	$	1	$	(328	)	$	508,179

	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

Schedule of Contractual Maturities of Short-term Investments

The following tables present the contractual maturities of the Company’s short-term investments as of April 30, 2018 and January 31, 2018 (in thousands):

	As of April 30, 2018				As of January 31, 2018
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(unaudited)
Due within one year	$	306,045	$	305,761	$	93,421	$	93,237
Due between one to five years	29,566		29,524		8,546		8,528
	$	335,611	$	335,285	$	101,967	$	101,765