Reconciliation of Earnings (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Oct. 31, 2018	Oct. 31, 2017
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Net income (loss)	$ (7,365)	$ (5,237)
Less: Preferred dividends on redeemable preferred stock	(536)
Net income (loss) attributable to common stockholders	$ (7,901)	$ (5,237)
Weighted average common shares outstanding	60,712	55,260
Weighted average common equivalent shares arising from dilutive stock options, restricted stock, convertible notes and convertible preferred stock	0	0
Weighted average number of common and potential common shares	60,712	55,260
Basic and diluted net loss per share attributable to common stockholders:	$ (0.13)	$ (0.09)