Cash Equivalents and Short-Term Investments - Schedule of Unrealized Position (Details) - USD ($) $ in Thousands	Jan. 31, 2020	Jul. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	$ 34,437	$ 56,548
Less than 12 months, unrealized losses	(21)	(62)
Greater than 12 months, fair value	21,121	18,356
Greater than 12 months, unrealized losses	(7)	(16)
Total fair value	55,558	74,904
Total unrealized losses	(28)	(78)
U.S. government agency securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	28,149	36,550
Less than 12 months, unrealized losses	(17)	(37)
Greater than 12 months, fair value	20,121	9,992
Greater than 12 months, unrealized losses	(6)	(13)
Total fair value	48,270	46,542
Total unrealized losses	(23)	(50)
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	6,288	14,279
Less than 12 months, unrealized losses	(4)	(16)
Greater than 12 months, fair value	1,000	8,364
Greater than 12 months, unrealized losses	(1)	(3)
Total fair value	7,288	22,643
Total unrealized losses	$ (5)	(19)
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value		5,719
Less than 12 months, unrealized losses		(9)
Greater than 12 months, fair value		0
Greater than 12 months, unrealized losses		0
Total fair value		5,719
Total unrealized losses		$ (9)

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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