Acquisitions (Summary Of Estimate Of Fair Value Of Identifiable Assets Acquired And Liabilities Assumed) (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Sep. 11, 2014
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired	$ 0	$ 182,500
PCMR [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables			$ 930
Business Acquisition, Purchase Price Allocation, Current Assets, Other Current Assets			3,075
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment			76,605
Business Acquisition, Purchase Price Allocation, Deferred Taxes Asset (Liab), Net, Noncurrent			7,428
Business Acquisition, Purchase Price Allocation, Real estate held for sale and investment			7,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill			27,650
Goodwill, Acquired During Period		92,516
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets			215,204
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable			1,935
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue			4,319
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			$ 6,254
Business Combination, Consideration Transferred		$ 208,950