Supplementary Balance Sheet Information (Components Of Accounts Payable And Accrued Liabilities) (Details) (USD $) In Thousands	Jul. 31, 2011	Jul. 31, 2010
Supplementary Balance Sheet Information
Trade payables	$ 55,456	$ 47,554
Real estate development payables	3,360	31,203
Deferred revenue	66,044	53,298
Deferred real estate and other deposits	11,741	42,891
Accrued salaries, wages and deferred compensation	26,350	21,425
Accrued benefits	22,107	23,547
Accrued interest	8,511	13,939
Other accruals	27,790	21,469
Total accounts payable and accrued liabilities	$ 221,359	$ 255,326