CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Apr. 30, 2019	Jul. 31, 2018
Accounts receivable, trade, allowance for doubtful accounts	$ 468	$ 480
Preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	4,965,000	4,965,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,400,000,000	1,400,000,000
Common stock, shares issued (in shares)	61,802,196	60,742,859
Common stock, shares outstanding (in shares)	61,802,196	60,742,859
Contingent Redeemable Preferred Stock
Preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	35,000	35,000
Preferred stock, shares issued (in shares)	35,000	35,000
Preferred stock, shares outstanding (in shares)	35,000	35,000