REVENUE, DEFERRED REVENUE AND DEFERRED COMMISSIONS - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue	$ 303,748	$ 289,413	$ 286,744	$ 275,552	$ 252,458	$ 205,670	$ 199,214	$ 188,561	$ 1,155,457	$ 845,903	$ 503,410
Software
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue									630,675	436,981	287,603
Hardware
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue									257,314	236,316	126,307
Support, entitlements and other services
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue	$ 79,098	$ 68,296	$ 63,574	$ 56,500	$ 50,986	$ 45,594	$ 41,001	$ 35,025	267,468	172,606	89,500
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue									$ 1,155,457	845,903	503,410
Accounting Standards Update 2014-09 [Member] \| Support, entitlements and other services
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue										$ 172,606	$ 89,500
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Software license term									1 year
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Software license term									5 years
Weighted Average
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Software license term									3 years 6 months