STOCK-BASED COMPENSATION (Details) (USD $)	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
STOCK-BASED COMPENSATION
Number of shares of common stock authorized for issue	5,500,000
Number of shares available to be issued	1,000,000
Stock-based compensation expense	$ 3,300,000	$ 2,700,000	$ 2,200,000
Income tax benefit recognized related to stock-based compensation	1,200,000	1,000,000	100,000
Stock Options
STOCK-BASED COMPENSATION
Vesting period	4 years
Expiration term	10 years
Unrecognized compensation cost related to stock option awards	1,600,000
Period over which unrecognized compensation expense is expected to be recognized	1 year 10 months 24 days
Number of Options
Outstanding, beginning of year (in shares)	3,624,907
Granted (in shares)	10,500
Exercised (in shares)	(65,325)
Forfeited (in shares)	(106,850)
Expired (in shares)	(255,949)
Outstanding, end of year (in shares)	3,207,283	3,624,907
Options exercisable, end of year (in shares)	2,099,758
Weighted-Average Exercise Price
Outstanding, beginning of year (in dollars per share)	$ 10.31
Granted (in dollars per share)	$ 5.15
Exercised (in dollars per share)	$ 2.30
Forfeited (in dollars per share)	$ 3.02
Expired (in dollars per share)	$ 23.49
Outstanding, end of year (in dollars per share)	$ 9.65	$ 10.31
Options exercisable, end of year (in dollars per share)	$ 13.09
Weighted-Average Remaining Contractual Life
Outstanding, end of year	6 years 25 days
Options exercisable, end of year	5 years 2 months 16 days
Aggregate Intrinsic Value
Outstanding, end of year	13,801,439
Options exercisable, end of year	7,335,791
Stock options, additional disclosure
Total intrinsic value of stock options exercised	300,000
Weighted-average fair values of option grants (in dollars per share)	$ 3.70	$ 2.51	$ 1.38
Fair value of stock options that vested	1,600,000	1,600,000	2,000,000
Weighted-average assumptions
Expected volatility (as a percent)	107.00%	101.40%	93.50%
Risk-free interest rate (as a percent)	0.50%	0.70%	1.00%
Expected lives in years	4 years	4 years	4 years
Dividend yield (as a percent)	0.00%	0.00%	0.00%
Restricted Share Awards
STOCK-BASED COMPENSATION
Period over which unrecognized compensation expense is expected to be recognized	1 year 8 months 12 days
Restricted share awards, additional disclosure
Unrecognized compensation cost related to restricted stock awards	3,300,000
Fair value of restricted share awards	$ 3,000,000	$ 200,000	$ 100,000
Number of Restricted Share Awards
Restricted share awards, beginning of year	1,473,497
Granted (in shares)	238,483
Vested (in shares)	(446,982)
Forfeited (in shares)	(33,375)
Restricted share awards, end of year	1,231,623	1,473,497
Weighted-Average Fair Value Per Award
Restricted share awards, beginning of year (in dollars per share)	$ 3.29
Granted (in dollars per share)	$ 5.88
Vested (in dollars per share)	$ 3.49
Forfeited (in dollars per share)	$ 3.19
Restricted share awards, end of year (in dollars per share)	$ 3.73	$ 3.29
Restricted stock and restricted stock units
STOCK-BASED COMPENSATION
Vesting period			3 years
Restricted stock and restricted stock units | Awards Granted From Fiscal Year 2007 to 2011
Restricted share awards, additional disclosure
Vesting percentage on the second and third anniversary of the date of the grant	25.00%
Vesting percentage on the fourth anniversary of the date of the grant	50.00%
Performance-based stock
Number of Restricted Share Awards
Restricted share awards, end of year	297,500	297,500