Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Series G convertible preferred stock [Member]	Series G-1 convertible preferred stock [Member]	Series H Convertible Preferred Stock [Member]	Convertible Preferred Stock [Member]	Convertible Preferred Stock [Member] Series G convertible preferred stock [Member]	Convertible Preferred Stock [Member] Series G-1 convertible preferred stock [Member]	Convertible Preferred Stock [Member] Series H Convertible Preferred Stock [Member]	Common Stock [Member]	Common Stock [Member] Series G-1 convertible preferred stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Series G convertible preferred stock [Member]	Additional Paid-in Capital [Member] Series G-1 convertible preferred stock [Member]	Additional Paid-in Capital [Member] Series H Convertible Preferred Stock [Member]	Accumulated Deficit [Member]
Beginning Balance, Shares at Jul. 31, 2013					14,797,535				3,003,076
Beginning Balance at Jul. 31, 2013	$ 27,336				$ 112				$ 23		$ 112,279				$ (85,078)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of convertible preferred stock in connection with acquisition, Shares						511,538	681,792
Issuance of convertible preferred stock in connection with acquisition		$ 9,603	$ 7,421			$ 4	$ 5					$ 9,599	$ 7,416
Issuance of stock, Shares								2,715,382
Issuance of stock, net of issuance costs				$ 59,874				$ 21						$ 59,853
Issuance of common stock upon exercise of options, Shares									545,370
Issuance of common stock upon exercise of options	456								$ 4		452
Issuance of common stock upon vesting of restricted stock units, Shares									70,655
Issuance of common stock upon vesting of restricted stock units	30								$ 1		29
Issuance of common stock upon exercise of warrants, Shares									311,741
Issuance of common stock upon exercise of warrants	2,838								$ 2		2,836
Issuance of restricted stock units in connection with InsightsOne acquisition	31										31
Stock-based compensation	2,726										2,726
Net loss	(60,793)														(60,793)
Ending Balance at Jul. 31, 2014	49,522				$ 142				$ 30		195,221				(145,871)
Ending Balance, Shares at Jul. 31, 2014					18,706,247				3,930,842
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of convertible preferred stock in connection with acquisition, Shares					0				5,115,000
Issuance of convertible preferred stock in connection with acquisition	76,847				$ 0				$ 5		76,842
Issuance of common stock upon exercise of options, Shares									465,385
Issuance of common stock upon exercise of options	434								$ 5		429
Issuance of common stock upon exercise of warrants, Shares									57,082
Issuance of common stock upon exercise of warrants	26								$ 0		26
Issuance of restricted stock units in connection with InsightsOne acquisition	(8)										(8)
Stock-based compensation	3,451										3,451
Net loss	(50,353)														(50,353)
Conversion of convertible preferred stock to common stock upon initial public offering, Shares					(18,614,597)				19,818,172
Conversion of convertible preferred stock to common stock upon initial public offering	0				$ (141)				$ (11)		152
Repurchase of stock, Shares							(91,650)
Repurchase of stock			(15)				$ (1)						(14)
Ending Balance at Jul. 31, 2015	79,904				$ 0				$ 29		276,099				(196,224)
Ending Balance, Shares at Jul. 31, 2015					0				29,386,481
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of options, Shares									625,496
Issuance of common stock upon exercise of options	1,162								$ 1		1,161
Stock-based compensation	8,388										8,388
Net loss	(41,512)														(41,512)
Repurchase of stock, Shares										(24,287)
Repurchase of stock			$ (18)							$ 0			$ (18)
Shares issued under employee stock purchase plan, Shares									296,411
Shares issued under employee stock purchase plan	2,057								$ 0		2,057
Restricted stock units vested (net), Shares									156,708
Restricted stock units vested (net)	0								$ 0		0
Shares withheld for taxes related to net share settlement	(531)										(531)
Ending Balance at Jul. 31, 2016	$ 49,450								$ 30		$ 287,156				$ (237,736)
Ending Balance, Shares at Jul. 31, 2016									30,440,809