Preliminary Allocations of Aggregate Purchase Price (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2013
2013 Acquisitions
Dec. 31, 2013
2013 Acquisitions
Customer relationships
Nov. 30, 2012
Power Fuels Merger
Nov. 30, 2012
Power Fuels Merger
Customer relationships
Dec. 31, 2012
Other 2012 Acquisitions
Dec. 31, 2012
Other 2012 Acquisitions
Customer relationships
Dec. 31, 2012
Other 2012 Acquisitions
Equipment
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]                    
Cash           $ 2,111        
Intangible Assets         400   145,000   9,270  
Accounts receivable       753   57,484   2,653    
Inventory           3,443        
Other assets       13   3,271        
Property, plant and equipment       41,942   287,818       21,108
Goodwill 408,696 415,176 90,008 341   304,031   12,452    
Accounts payable and accrued liabilities       (189)   (24,291)        
Debt           (150,367)        
Other long-term liabilities       (302)       (8,768)    
Deferred income tax liabilities, net           (129,711)        
Other liabilities               (613)    
Total       $ 42,958   $ 498,789   $ 36,102