CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income
Beginning balance (in shares) at Jul. 31, 2018		60,742,859,000
Beginning balance at Jul. 31, 2018	$ 107,628	$ 608	$ 7,467,855	$ (7,363,569)	$ 2,734
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(7,365)			(7,365)
Effect of adoption of accounting standards	6,138
Preferred dividends	(536)			(536)
Issuance of common stock pursuant to employee stock purchase plan and stock option exercises (in shares)		3,107,000
Issuance of common stock pursuant to employee stock purchase plan and stock option exercises	6		6
Restricted stock grants (in shares)		640,922,000
Restricted stock grants	0	$ 6	(6)
Share-based compensation	792		792
Other comprehensive items	(1,232)				(1,232)
Ending balance (in shares) at Oct. 31, 2018		61,386,888,000
Ending balance at Oct. 31, 2018	$ 105,431	$ 614	7,468,647	(7,365,332)	1,502
Beginning balance (in shares) at Jul. 31, 2019	61,805,856,000	61,805,856,000
Beginning balance at Jul. 31, 2019	$ 52,692	$ 618	7,477,327	(7,426,287)	1,034
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	4,792			4,792
Preferred dividends	(536)			(536)
Issuance of common stock pursuant to employee stock purchase plan and stock option exercises (in shares)		4,397,000
Issuance of common stock pursuant to employee stock purchase plan and stock option exercises	2		2
Share-based compensation	176		176
Other comprehensive items	$ 11				11
Ending balance (in shares) at Oct. 31, 2019	61,810,253,000	61,810,253,000
Ending balance at Oct. 31, 2019	$ 57,137	$ 618	$ 7,477,505	$ (7,422,031)	$ 1,045