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, 2019		61,805,856
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 (loss) income	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
Issuance of common stock pursuant to employee stock purchase plan	2		2
Share-based compensation	176		176
Other comprehensive items	11				11
Ending balance (in shares) at Oct. 31, 2019		61,810,253
Ending balance at Oct. 31, 2019	$ 57,137	$ 618	7,477,505	(7,422,031)	1,045
Beginning balance (in shares) at Jul. 31, 2020	62,787,919	62,787,919
Beginning balance at Jul. 31, 2020	$ 48,818	$ 628	7,478,047	(7,433,700)	3,843
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(3,551)			(3,551)
Preferred dividends	(537)			(537)
Issuance of common stock pursuant to employee stock purchase plan and stock option exercises (in shares)		6,982
Issuance of common stock pursuant to employee stock purchase plan	3		3
Restricted stock forfeitures, net of issuance (in shares)		(932)
Share-based compensation	188		188
Other comprehensive items	$ 2,973				2,973
Ending balance (in shares) at Oct. 31, 2020	62,793,969	62,793,969
Ending balance at Oct. 31, 2020	$ 47,894	$ 628	$ 7,478,238	$ (7,437,788)	$ 6,816