Property, Plant and Equipment, Net (Details) - USD ($)
$ in Millions
Jun. 30, 2021
Dec. 31, 2020
Property, Plant and Equipment [Line Items]    
Total property plant and equipment $ 1,888.9 $ 1,846.7
Less: accumulated depreciation and depletion (1,055.1) (995.0)
Property, plant and equipment, net 833.8 851.7
Land, buildings and structures, and leasehold improvements    
Property, Plant and Equipment [Line Items]    
Total property plant and equipment 540.1 544.5
Machinery and equipment    
Property, Plant and Equipment [Line Items]    
Total property plant and equipment 1,076.1 1,035.4
Office furniture and equipment    
Property, Plant and Equipment [Line Items]    
Total property plant and equipment 55.1 50.7
Mineral interests    
Property, Plant and Equipment [Line Items]    
Total property plant and equipment 174.0 172.4
Construction in progress    
Property, Plant and Equipment [Line Items]    
Total property plant and equipment $ 43.6 $ 43.7