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

Operating Segment Information and Concentrations of Risk - Summary of Geographical Information 2 (Details)

v3.22.1
Operating Segment Information and Concentrations of Risk - Summary of Geographical Information 2 (Details) - USD ($)
$ in Millions
 12 Months Ended
Mar. 31, 2022
Mar. 31, 2021
Mar. 31, 2020
Segment Reporting Information [Line Items]      
Selling, general and administrative expenses $ 461.2 $ 389.6 $ 415.8
Research and development costs 38.0 34.3 32.8
Property, plant and equipment 0.4 2.0 64.5
Right-of-use assets     11.2
Intangible assets     1.4
Inventories     2.9
Goodwill     0.2
Asset Retirement Obligations     5.8
Other     1.2
Restructuring expenses 0.0 11.1 84.4
Property, Plant and Equipment      
Segment Reporting Information [Line Items]      
Property, plant and equipment   61.7  
General Corporate      
Segment Reporting Information [Line Items]      
Right-of-use assets     0.0
Intangible assets     1.4
Inventories     0.0
Goodwill     0.0
Asset Retirement Obligations     0.0
Other     0.0
Restructuring expenses     1.4
General Corporate | Property, Plant and Equipment      
Segment Reporting Information [Line Items]      
Property, plant and equipment   0.0  
North America Fiber Cement      
Segment Reporting Information [Line Items]      
Research and development costs 5.3 5.6 5.3
Property, plant and equipment 0.4 2.0 44.0
North America Fiber Cement | Cost of Sales      
Segment Reporting Information [Line Items]      
Other 0.4 2.0 2.8
North America Fiber Cement | Operating Segments      
Segment Reporting Information [Line Items]      
Right-of-use assets     0.0
Intangible assets     0.0
Inventories     0.0
Goodwill     0.0
Asset Retirement Obligations     0.0
Other     0.0
Restructuring expenses     41.2
North America Fiber Cement | Operating Segments | Property, Plant and Equipment      
Segment Reporting Information [Line Items]      
Property, plant and equipment   41.2  
Asia Pacific Fiber Cement      
Segment Reporting Information [Line Items]      
Research and development costs 1.5 1.1 1.8
Property, plant and equipment 0.0 0.0 15.0
Inventories     2.9
Asia Pacific Fiber Cement | Other liabilities - non-current      
Segment Reporting Information [Line Items]      
Asset retirement obligation     8.0
Asia Pacific Fiber Cement | Operating Segments      
Segment Reporting Information [Line Items]      
Right-of-use assets     11.2
Intangible assets     0.0
Inventories     2.9
Goodwill     0.2
Asset Retirement Obligations     5.8
Other     1.2
Restructuring expenses     36.3
Asia Pacific Fiber Cement | Operating Segments | Property, Plant and Equipment      
Segment Reporting Information [Line Items]      
Property, plant and equipment   15.0  
Europe Building Products      
Segment Reporting Information [Line Items]      
Research and development costs 0.9 1.6 1.7
Property, plant and equipment 0.0 0.0 5.5
Europe Building Products | Operating Segments      
Segment Reporting Information [Line Items]      
Right-of-use assets     0.0
Intangible assets     0.0
Inventories     0.0
Goodwill     0.0
Asset Retirement Obligations     0.0
Other     0.0
Restructuring expenses     5.5
Europe Building Products | Operating Segments | Property, Plant and Equipment      
Segment Reporting Information [Line Items]      
Property, plant and equipment   5.5  
Research and Development      
Segment Reporting Information [Line Items]      
Selling, general and administrative expenses 4.1 2.9 3.0
Research and development costs $ 30.3 $ 26.0 $ 24.0