Supplementary Balance Sheet Information (Components Of Accounts Payable And Accrued Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013	Jul. 31, 2012	Jan. 31, 2012
Balance Sheet Related Disclosures [Abstract]
Trade payables	$ 63,914	$ 56,508	$ 75,751
Deferred revenue	117,812	78,793	104,570
Accrued salaries, wages and deferred compensation	30,838	21,242	24,143
Accrued benefits	21,870	20,216	23,256
Deposits	26,411	12,031	20,730
Accrued interest	7,896	8,015	7,914
Other accruals	48,763	30,733	45,109
Total accounts payable and accrued liabilities	$ 317,504	$ 227,538	$ 301,473