Other Intangible Assets (Details) (USD $)	12 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2006
Finite-Lived Intangible Assets [Line Items]
Gross carrying value	$ 17,687,000	$ 17,473,000
Accumulated amortization	5,231,000	4,631,000
Net	12,456,000	12,842,000
Goodwill as a result of reverse merge transaction				10,660,000
Amortization included in general and administrative expense	600,000	653,000	879,000
Future amortization expense [Abstract]
2013	589,000
2014	589,000
2015	588,000
2016	573,000
2017	570,000
Proprietary know-how [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying value	4,057,000	4,057,000
Accumulated amortization	2,039,000	1,792,000
Net	2,018,000	2,265,000
Goodwill as a result of reverse merge transaction				4,057,000
Trademark [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying value	5,923,000	5,923,000
Accumulated amortization	0	0
Net	5,923,000	5,923,000
Licensing agreement [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying value	5,834,000	5,834,000
Accumulated amortization	2,498,000	2,230,000
Net	3,336,000	3,604,000
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying value	1,873,000	1,659,000
Accumulated amortization	694,000	609,000
Net	1,179,000	1,050,000
Amortization included in general and administrative expense	$ 600,000	$ 653,000	$ 879,000