Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Property, Plant and Equipment - Additional Information (Detail)

v3.20.1
Property, Plant and Equipment - Additional Information (Detail)
$ in Millions
 12 Months Ended
Mar. 31, 2020
USD ($)
plant
Mar. 31, 2019
USD ($)
Mar. 31, 2018
USD ($)
Property, Plant and Equipment [Line Items]      
Depreciation expense $ 125.4 $ 109.6 $ 88.9
Asset impairments 84.4 15.9 0.0
Property, plant and equipment, net 1,341.7 1,388.4  
Other impairment charges 1.2    
Cost of Sales      
Property, Plant and Equipment [Line Items]      
Impairment charges related to decision to shut down facility   0.4  
Other impairment charges 2.8 0.4 $ 0.7
Shut Down of Summerville, South Carolina Facility      
Property, Plant and Equipment [Line Items]      
Impairment charges related to decision to shut down facility 12.0    
Impairment charge, difference between carrying value and fair value 22.1    
Costs to sell 10.1    
Non-Core Assets      
Property, Plant and Equipment [Line Items]      
Impairment charges related to decision to shut down facility $ 29.2    
Number of plants | plant 4    
North America Fiber Cement      
Property, Plant and Equipment [Line Items]      
Asset impairments $ 41.2 2.6  
Impairment charges related to decision to shut down facility   2.6  
Other impairment charges 0.0    
North America Fiber Cement | Cost of Sales      
Property, Plant and Equipment [Line Items]      
Other impairment charges 2.8    
Asia Pacific Fiber Cement      
Property, Plant and Equipment [Line Items]      
Asset impairments 36.3    
Other impairment charges 1.2    
Asia Pacific Fiber Cement | Penrose Plant Assets      
Property, Plant and Equipment [Line Items]      
Property, plant and equipment, net 2.6    
Asia Pacific Fiber Cement | Exit of Business      
Property, Plant and Equipment [Line Items]      
Asset impairments 14.0    
Impairment charges related to decision to shut down facility 1.0    
Europe Building Products      
Property, Plant and Equipment [Line Items]      
Asset impairments 5.5    
Other impairment charges 0.0    
Europe Building Products | Non-Core Assets      
Property, Plant and Equipment [Line Items]      
Asset impairments $ 5.5    
Other Businesses      
Property, Plant and Equipment [Line Items]      
Asset impairments   6.1  
Impairment charges related to decision to shut down facility   $ 6.1