Income Taxes (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
	Dec. 31, 2007	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009	Jul. 31, 2008
Net operating loss carryforwards recognized	$ 8,000,000
Net operating loss carryforwards amount		73,800,000
Tax refund on amended returns		6,200,000
Reduction in federal tax liability		19,600,000
Unrecognized tax benefits		26,573,000	27,048,000	27,320,000	17,796,000
Unrecognized tax benefits, income tax penalties and interest accrued		1,900,000	2,200,000
Income tax examination, penalties and interest expense		(200,000)	(200,000)	500,000
Maximum [Member]
Reversal amount of other long-term liabilities and accrued interest and penalties		27,600,000
Minimum [Member]
Reversal amount of other long-term liabilities and accrued interest and penalties		0
State and Local Jurisdiction [Member]
NOL carryforwards expiration date		July 31, 2031
Operating loss carryforwards, valuation allowance		1,600,000
State operating loss carryforwards		30,000,000
Operating loss carryforward acquired		$ 4,900,000