Income Taxes (Details 2) (USD $)	12 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Deferred tax assets:
North America current liabilities	$ 440,000	$ 1,154,000
North America non-current assets	(9,425,000)	(10,213,000)
UK non-current liabilities	10,057,000	9,748,000
Net deferred tax liability	(1,072,000)	(689,000)
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals [Abstract]
Unrecognized tax benefits	13,200,000	9,900,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance as of August 1	18,144,000	15,965,000
Increases related to current year tax positions	1,592,000	4,514,000
Prior year tax positions:
Prior year increase	519,000	74,000
Prior year decrease	(531,000)	(532,000)
Cash settlement		(302,000)
Lapse of statute of limitations	(930,000)	(1,575,000)
Balance at July 31	18,794,000	18,144,000	15,965,000
Interest and penalties related to income tax	6,000,000
Recognized tax benefit	3,600,000	6,200,000	4,600,000
Retained Earnings, Undistributed Earnings from Equity Method Investees	$ 42,000,000