XML 87 R12.htm IDEA: XBRL DOCUMENT v2.4.0.6
Property, Plant, Equipment and Mineral Rights and Reserves
12 Months Ended
Dec. 31, 2012
Property, Plant, Equipment and Mineral Rights and Reserves [Abstract]  
Property, Plant, Equipment and Mineral Rights and Reserves
(4)           Property, Plant, Equipment and Mineral Rights and Reserves

Property, plant, equipment and mineral rights and reserves consisted of the following:

  
December 31,
 
   
2012
  
2011
 
Mineral rights and reserves
 $48.6  $52.5 
Land
  13.0   12.1 
Buildings and improvements
  104.9   97.5 
Machinery and equipment
  414.5   362.0 
Construction in progress
  32.6   25.2 
    613.6   549.3 
          

The range of useful lives to depreciate plant and equipment is as follows:

 
 
Buildings and improvements
3-50 years
Machinery and equipment
1-24 years
 
 
 
Depreciation and depletion were charged to income as follows:

   
2012
  
2011
  
2010
 
Depreciation expense
 $39.3  $35.0  $30.1 
Depletion expense
  1.6   2.6   1.2 
    40.9   37.6   31.3