Business and Summary of Significant Accounting Policies - Narrative (Details)		1 Months Ended	12 Months Ended
	Mar. 31, 2018 $ / shares shares	Mar. 31, 2018 USD ($) $ / shares shares	Jul. 31, 2019 USD ($) segment shares	Jul. 31, 2018 USD ($) shares	Jul. 31, 2017 USD ($)	Aug. 01, 2018 USD ($)	Aug. 01, 2017 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reverse stock split, ratio		0.6667
Sale of stock, number of shares issued in transaction (in shares) | shares		13,800,000
Sale of stock, price per share (in dollars per share) | $ / shares	$ 16.00	$ 16.00
Sale of stock, net proceeds		$ 205,300,000
Payments for underwriting expense		15,500,000		$ 15,456,000
Offering costs		$ 6,200,000		6,164,000
Conversion of redeemable convertible preferred stock to common stock upon initial public offering (in shares) | shares	72,500,750
Conversion ratio	1	1
Foreign currency loss			$ 300,000	100,000	$ 100,000
Number of reportable segments | segment			1
Number of operating segments | segment			1
Contract with customer, liability, revenue recognized			$ 143,900,000	85,300,000	58,500,000
Revenue, remaining performance obligation			$ 554,200,000
Capitalized contract cost, amortization period			5 years
Accrued sales commission			$ 9,000,000.0	10,000,000.0
Investment impairment			0	0
Restricted cash			0	600,000
Capitalized software costs			3,700,000	1,800,000	400,000
Capitalized software, amortization expense			$ 1,000,000.0	900,000	1,200,000
Requisite service period			4 years
Advertising expense			$ 8,600,000	$ 3,400,000	$ 1,800,000
Preferred stock, shares issued (in shares) | shares			0	0
Preferred stock, shares outstanding (in shares) | shares			0	0
Cumulative effect of accounting change						$ 0	$ 0
Subscription and Support | Transferred over Time | Sales Revenue, Net | Product Concentration Risk
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Concentration risk percentage			99.00%	99.00%	99.00%
Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change						300,000	(438,000)
Additional Paid-In Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change						(300,000)	$ 438,000
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract with customer, term of contract			1 year
Contracts with customers, payment terms			30 days
Estimated Useful Life			3 years
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract with customer, term of contract			3 years
Contracts with customers, payment terms			90 days
Estimated Useful Life			5 years
ASU 2018-07 | Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change						300,000
ASU 2018-07 | Additional Paid-In Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change						$ (300,000)
Capitalized internal-use software
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated Useful Life			3 years