CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' (DEFICIT) EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income
Beginning balance (in shares) at Jul. 31, 2020		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	(33,376)			(33,376)
Preferred dividends	(1,586)			(1,586)
Issuance of common stock pursuant to employee stock purchase plan (in shares)		8,792
Issuance of common stock pursuant to employee stock purchase plan	4		4
Restricted stock grants (in shares)		332,578
Restricted stock grants	0	$ 3	(3)
Restricted stock forfeitures (in shares)		(32,895)
Share-based compensation	443		443
Other comprehensive items	5,281				5,281
Ending balance (in shares) at Apr. 30, 2021		63,096,394
Ending balance at Apr. 30, 2021	19,584	$ 631	7,478,491	(7,468,662)	9,124
Beginning balance (in shares) at Jan. 31, 2021		63,000,314
Beginning balance at Jan. 31, 2021	47,747	$ 630	7,478,395	(7,440,514)	9,236
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(27,629)			(27,629)
Preferred dividends	(519)			(519)
Issuance of common stock pursuant to employee stock purchase plan (in shares)		362
Issuance of common stock pursuant to employee stock purchase plan	0
Restricted stock grants (in shares)		95,718
Restricted stock grants	0	$ 1	(1)
Share-based compensation	97		97
Other comprehensive items	(112)				(112)
Ending balance (in shares) at Apr. 30, 2021		63,096,394
Ending balance at Apr. 30, 2021	$ 19,584	$ 631	7,478,491	(7,468,662)	9,124
Beginning balance (in shares) at Jul. 31, 2021	63,099,496	63,099,496
Beginning balance at Jul. 31, 2021	$ 6,212	$ 632	7,478,638	(7,480,220)	7,162
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(12,271)			(12,271)
Preferred dividends	(1,611)			(1,611)
Issuance of common stock pursuant to employee stock purchase plan (in shares)		499
Restricted stock grants (in shares)		348,789
Restricted stock grants	0	$ 3	(3)
Restricted stock forfeitures (in shares)		(3,050,000)
Restricted stock forfeitures	0	$ (31)	31
Share-based compensation	519		519
Other comprehensive items	$ (2,276)				(2,276)
Ending balance (in shares) at Apr. 30, 2022	60,398,784	60,398,784
Ending balance at Apr. 30, 2022	$ (9,427)	$ 604	7,479,185	(7,494,102)	4,886
Beginning balance (in shares) at Jan. 31, 2022		60,457,720
Beginning balance at Jan. 31, 2022	(36,740)	$ 605	7,479,073	(7,523,765)	7,347
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	30,200			30,200
Preferred dividends	(537)			(537)
Restricted stock grants (in shares)		141,064
Restricted stock grants	0	$ 1	(1)
Restricted stock forfeitures (in shares)		(200,000)
Restricted stock forfeitures	0	$ (2)	2
Share-based compensation	111		111
Other comprehensive items	$ (2,461)				(2,461)
Ending balance (in shares) at Apr. 30, 2022	60,398,784	60,398,784
Ending balance at Apr. 30, 2022	$ (9,427)	$ 604	$ 7,479,185	$ (7,494,102)	$ 4,886