Goodwill and Intangible Assets (Details Textual) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2012 Reporting_unit Segment	Jan. 31, 2011	Jul. 31, 2011
Goodwill and Intangible Assets (Textual) [Abstract]
Increase (decrease) needed to revise carrying amount of goodwill to fair value	$ 115,688		$ 115,688		$ 133,436
Decrease in recorded value of goodwill			133,436
Goodwill impairment charge	115,688		115,688
Amortization of Intangible Assets	4,075	5,123	8,155	10,270
Projected Future amortization expense, year one			16,132
Projected Future amortization expense, year two			10,320
Projected Future amortization expense, year three			5,438
Projected Future amortization expense, year four			5,102
Projected Future amortization expense, year five			$ 4,040
Number of reporting units identified for impairment analysis			7
Number of reporting segments			3