XML 134 R51.htm IDEA: XBRL DOCUMENT v2.4.0.8
Property, plant and equipment (Details 3) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Property, plant and equipment [Line Items]      
Interest capitalized $ 6,033 $ 8,659 $ 10,821
AFUDC - borrowed 2,767 2,483 1,666
AFUDC - equity 3,322 4,530 2,587
Property, plant and equipment 8,803,866 8,107,751  
Less accumulated depreciation, depletion and amortization 3,872,487 3,608,912 3,361,208
Net property, plant and equipment 4,931,379 4,498,839 4,285,014
BOE average rate for amortization under units-of-production method (in dollars per BOE) 17.41 15.28 12.25
Oil and natural gas properties not subject to amortization 124,869 191,794 232,462
Electric:
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 1,315,822 [1] 1,150,584 [1] 1,068,524 [1]
Natural gas distribution:
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 1,776,901 [1] 1,689,950 [1] 1,568,866 [1]
Pipeline and energy services:
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 962,172 816,533 719,291
Exploration and production:
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 3,060,848 2,764,560 2,615,146
Construction materials and contracting:
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 1,510,355 1,504,981 1,499,852
Construction services:
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 134,948 130,624 124,796
Other:
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 49,997 50,519 49,747
Regulated: | Electric: | Generation
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 570,394 546,011  
Weighted average depreciable life in years 42 years    
Regulated: | Electric: | Distribution
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 308,202 276,446  
Weighted average depreciable life in years 39 years    
Regulated: | Electric: | Transmission
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 196,824 180,543  
Weighted average depreciable life in years 48 years    
Regulated: | Electric: | Construction in progress
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 141,365 62,123  
Regulated: | Electric: | Other
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 99,037 85,461  
Weighted average depreciable life in years 14 years    
Regulated: | Natural gas distribution: | Distribution
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 1,384,587 1,308,314  
Weighted average depreciable life in years 40 years    
Regulated: | Natural gas distribution: | Construction in progress
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 46,763 71,679  
Regulated: | Natural gas distribution: | Other
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 345,551 309,957  
Weighted average depreciable life in years 25 years    
Regulated: | Pipeline and energy services: | Transmission
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 418,594 403,126  
Weighted average depreciable life in years 52 years    
Regulated: | Pipeline and energy services: | Gathering
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 39,597 42,420  
Weighted average depreciable life in years 19 years    
Regulated: | Pipeline and energy services: | Storage
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 42,939 42,058  
Weighted average depreciable life in years 51 years    
Regulated: | Pipeline and energy services: | Construction in progress
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 6,937 13,667  
Regulated: | Pipeline and energy services: | Other
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 39,504 38,386  
Weighted average depreciable life in years 29 years    
Nonregulated: | Eliminations
      
Property, plant and equipment [Line Items]      
Property, plant and equipment (7,177) 0  
Nonregulated: | Pipeline and energy services: | Midstream
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 213,063 233,840  
Weighted average depreciable life in years 17 years    
Nonregulated: | Pipeline and energy services: | Construction in progress
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 188,641 29,657  
Nonregulated: | Pipeline and energy services: | Other
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 12,897 13,379  
Weighted average depreciable life in years 11 years    
Nonregulated: | Exploration and production: | Oil and natural gas properties
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 3,017,879 [2] 2,723,356 [2]  
Nonregulated: | Exploration and production: | Other
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 42,969 41,204  
Weighted average depreciable life in years 8 years    
Nonregulated: | Construction materials and contracting: | Land
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 125,551 126,788  
Nonregulated: | Construction materials and contracting: | Buildings and improvements
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 70,000 73,884  
Weighted average depreciable life in years 19 years    
Nonregulated: | Construction materials and contracting: | Machinery, vehicles and equipment
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 906,774 899,592  
Weighted average depreciable life in years 12 years    
Nonregulated: | Construction materials and contracting: | Construction in progress
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 13,315 11,165  
Nonregulated: | Construction materials and contracting: | Aggregate reserves
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 394,715 [3] 393,552 [3]  
Nonregulated: | Construction services: | Land
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 4,821 4,723  
Nonregulated: | Construction services: | Buildings and improvements
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 16,628 16,563  
Weighted average depreciable life in years 20 years    
Nonregulated: | Construction services: | Machinery, vehicles and equipment
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 105,991 100,445  
Weighted average depreciable life in years 6 years    
Nonregulated: | Construction services: | Other
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 7,508 8,893  
Weighted average depreciable life in years 4 years    
Nonregulated: | Other: | Land
      
Property, plant and equipment [Line Items]      
Property, plant and equipment 2,837 2,837  
Nonregulated: | Other: | Other
      
Property, plant and equipment [Line Items]      
Property, plant and equipment $ 47,160 $ 47,682  
Weighted average depreciable life in years 23 years    
[1] Includes allocations of common utility property.
[2] Amortized on the units-of-production method based on total proved reserves at a BOE average rate of $17.41, $15.28 and $12.25 for the years ended December 31, 2013, 2012 and 2011, respectively. Includes oil and natural gas properties accounted for under the full-cost method, of which $124.9 million and $191.8 million were excluded from amortization at December 31, 2013 and 2012, respectively.
[3] Depleted on the units-of-production method.