Acquisitions (Summary Of Estimate Of Fair Value Of Identifiable Assets Acquired And Liabilities Assumed) (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jan. 31, 2016
Jul. 31, 2015
Oct. 31, 2014
Jan. 31, 2016
Jan. 31, 2015
Jan. 19, 2016
Jun. 30, 2015
Sep. 11, 2014
Business Acquisition [Line Items]                
Payments to Acquire Businesses, Net of Cash Acquired       $ 20,245 $ 182,500      
Wilmot [Member]                
Business Acquisition [Line Items]                
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment           $ 12,500    
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill           400    
Goodwill, Acquired During Period $ 7,500              
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable           $ 400    
Business Combination, Consideration Transferred $ 20,200              
Perisher [Member]                
Business Acquisition [Line Items]                
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables             $ 1,494  
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment             126,287  
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill             5,458  
Goodwill, Acquired During Period   $ 31,657            
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets             170,280  
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable             11,394  
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue             15,906  
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities             $ 45,729  
Business Combination, Consideration Transferred   $ 124,551            
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