Annual and transition report of foreign private issuers [Sections 13 or 15(d)]

Segment and Geographic Information - Summary of Operating Segments (Details)

v3.25.1
Segment and Geographic Information - Summary of Operating Segments (Details) - USD ($)
$ in Millions
 12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Segment Reporting Information [Line Items]      
Net sales $ 3,877.5 $ 3,936.3 $ 3,777.1
Cost of goods sold 2,372.5 2,347.9 2,465.1
Gross profit 1,505.0 1,588.4 1,312.0
Selling, general and administrative expenses 596.2 602.2 494.0
Restructuring expenses 50.3 20.1 0.0
Operating income 655.9 767.4 741.4
Operating Segments      
Segment Reporting Information [Line Items]      
Net sales 3,877.5 3,936.3 3,777.1
Cost of goods sold 2,372.5 2,347.9 2,465.1
Gross profit 1,505.0 1,588.4 1,312.0
Selling, general and administrative expenses 451.7 443.2 366.7
Restructuring expenses 50.3    
Other expenses 13.1 13.0 8.5
Operating income 989.9 1,132.2 936.8
General Corporate and R&D      
Segment Reporting Information [Line Items]      
Operating income 334.0 364.8 195.4
North America Fiber Cement      
Segment Reporting Information [Line Items]      
Net sales 2,863.3 2,891.4 2,787.6
North America Fiber Cement | Operating Segments      
Segment Reporting Information [Line Items]      
Net sales 2,863.3 2,891.4 2,787.6
Cost of goods sold 1,721.4 1,674.8 1,781.8
Gross profit 1,141.9 1,216.6 1,005.8
Selling, general and administrative expenses 291.7 287.1 232.8
Restructuring expenses 0.0    
Other expenses 9.3 8.4 5.5
Operating income 840.9 921.1 767.5
Asia Pacific Fiber Cement      
Segment Reporting Information [Line Items]      
Net sales 519.9 562.8 539.2
Asia Pacific Fiber Cement | Operating Segments      
Segment Reporting Information [Line Items]      
Net sales 519.9 562.8 539.2
Cost of goods sold 301.2 335.4 338.9
Gross profit 218.7 227.4 200.3
Selling, general and administrative expenses 56.0 60.0 56.2
Restructuring expenses 50.3    
Other expenses 1.4 1.3 1.3
Operating income 111.0 166.1 142.8
Europe Building Products      
Segment Reporting Information [Line Items]      
Net sales 494.3 482.1 450.3
Europe Building Products | Operating Segments      
Segment Reporting Information [Line Items]      
Net sales 494.3 482.1 450.3
Cost of goods sold 349.9 337.7 344.4
Gross profit 144.4 144.4 105.9
Selling, general and administrative expenses 104.0 96.1 77.7
Restructuring expenses 0.0    
Other expenses 2.4 3.3 1.7
Operating income $ 38.0 $ 45.0 $ 26.5