Supplementary Balance Sheet Information (Components Of Accounts Payable And Accrued Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2014	Jul. 31, 2013	Apr. 30, 2013
Balance Sheet Related Disclosures [Abstract]
Trade payables	$ 48,406	$ 61,364	$ 59,515
Deferred revenue	93,135	93,759	81,092
Accrued salaries, wages and deferred compensation	35,221	27,946	28,563
Accrued benefits	25,468	19,787	24,002
Deposits	17,772	14,331	12,173
Accrued interest	13,549	8,018	13,543
Other accruals	31,226	44,314	27,464
Total accounts payable and accrued liabilities	$ 264,777	$ 269,519	$ 246,352

Carrying value as of the balance sheet date of obligations, excluding pension and other postretirement benefits, incurred through that date and payable for perquisites provided to employees pertaining to services received from them. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying value as of the balance sheet date of the obligations incurred through that date and payable for employees' services provided. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable arising from transactions not otherwise specified in the taxonomy. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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