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

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

v3.21.1
Operating Segment Information and Concentrations of Risk - Summary of Operating Segments (Details) - USD ($)
$ in Millions
 12 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Mar. 31, 2019
Segment Reporting Information [Line Items]      
Net sales $ 2,908.7 $ 2,606.8 $ 2,506.6
Operating income 472.8 342.5 351.6
Depreciation and amortization 135.0 131.5 119.4
Total Identifiable Assets 4,089.0 4,028.3  
Operating Segments      
Segment Reporting Information [Line Items]      
Operating income 719.0 472.0 432.4
Total Identifiable Assets 2,417.3 2,391.4  
General Corporate      
Segment Reporting Information [Line Items]      
Operating income (246.2) (129.5) (80.8)
Depreciation and amortization 2.8 3.2 4.3
Total Identifiable Assets 1,671.7 1,636.9  
North America Fiber Cement      
Segment Reporting Information [Line Items]      
Net sales 2,040.2 1,816.4 1,676.9
North America Fiber Cement | Operating Segments      
Segment Reporting Information [Line Items]      
Operating income 585.5 429.3 382.5
Depreciation and amortization 89.1 88.7 80.2
Total Identifiable Assets 1,273.9 1,320.0  
Asia Pacific Fiber Cement      
Segment Reporting Information [Line Items]      
Net sales 458.2 418.4 446.8
Asia Pacific Fiber Cement | Operating Segments      
Segment Reporting Information [Line Items]      
Operating income 124.8 58.5 99.8
Depreciation and amortization 13.9 12.7 12.8
Total Identifiable Assets 371.0 314.3  
Europe Building Products      
Segment Reporting Information [Line Items]      
Net sales 410.3 371.4 368.3
Europe Building Products | Operating Segments      
Segment Reporting Information [Line Items]      
Operating income 37.6 11.2 10.0
Depreciation and amortization 28.0 25.6 18.7
Total Identifiable Assets 762.1 748.5  
Other Businesses      
Segment Reporting Information [Line Items]      
Net sales 0.0 0.6 14.6
Other Businesses | Operating Segments      
Segment Reporting Information [Line Items]      
Operating income 0.0 0.0 (30.9)
Depreciation and amortization 0.0 0.2 2.3
Research and Development | Operating Segments      
Segment Reporting Information [Line Items]      
Operating income (28.9) (27.0) (29.0)
Depreciation and amortization 1.2 1.1 $ 1.1
Total Identifiable Assets $ 10.3 $ 8.6