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 (Detail)

v3.20.1
Operating Segment Information and Concentrations of Risk - Summary of Operating Segments (Detail) - USD ($)
$ in Millions
 12 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Mar. 31, 2018
Segment Reporting Information [Line Items]      
Net sales $ 2,606.8 $ 2,506.6 $ 2,054.5
Total operating income 342.5 351.6 229.2
Net interest expense (54.4) (50.1) (29.5)
Loss on early debt extinguishment 0.0 (1.0) (26.1)
Other (expense) income (0.1) 0.1 0.7
Income before income taxes 288.0 300.6 174.3
Depreciation and amortization 131.5 119.4 92.0
Total Identifiable Assets 4,028.3 4,032.6  
Operating Segments      
Segment Reporting Information [Line Items]      
Total operating income 472.0 432.4 453.9
Total Identifiable Assets 2,391.4 2,345.7  
General Corporate      
Segment Reporting Information [Line Items]      
Total operating income (129.5) (80.8) (224.7)
Depreciation and amortization 3.2 4.3 3.3
Total Identifiable Assets 1,636.9 1,686.9  
North America Fiber Cement      
Segment Reporting Information [Line Items]      
Net sales 1,816.4 1,676.9 1,578.1
Depreciation and amortization 88.7 80.2 72.5
North America Fiber Cement | Operating Segments      
Segment Reporting Information [Line Items]      
Total operating income 429.3 382.5 381.9
Total Identifiable Assets 1,320.0 1,280.2  
International Fiber Cement | Operating Segments      
Segment Reporting Information [Line Items]      
Total Identifiable Assets 314.3 328.8  
Asia Pacific Fiber Cement      
Segment Reporting Information [Line Items]      
Net sales 418.4 446.8 425.4
Depreciation and amortization 12.7 12.8 12.6
Asia Pacific Fiber Cement | Operating Segments      
Segment Reporting Information [Line Items]      
Total operating income 58.5 99.8 108.1
Europe Building Products      
Segment Reporting Information [Line Items]      
Net sales 371.4 368.3 36.3
Depreciation and amortization 25.6 18.7 0.1
Europe Building Products | Operating Segments      
Segment Reporting Information [Line Items]      
Total operating income 11.2 10.0 0.3
Total Identifiable Assets 748.5 717.7  
Other Businesses      
Segment Reporting Information [Line Items]      
Net sales 0.6 14.6 14.7
Depreciation and amortization 0.2 2.3 2.1
Other Businesses | Operating Segments      
Segment Reporting Information [Line Items]      
Total operating income 0.0 (30.9) (8.6)
Total Identifiable Assets 0.0 10.9  
Research and Development      
Segment Reporting Information [Line Items]      
Depreciation and amortization 1.1 1.1 1.4
Research and Development | Operating Segments      
Segment Reporting Information [Line Items]      
Total operating income (27.0) (29.0) $ (27.8)
Total Identifiable Assets $ 8.6 $ 8.1