v3.26.1
Segment Information - Schedule of Operating Segments (Details) - USD ($)
$ in Millions
 3 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting [Line Items]    
Net sales $ 1,474.6 $ 899.9
Cost of goods sold 925.9 563.0
Gross profit 548.7 336.9
Selling, general and administrative expenses 295.4 156.1
Restructuring expenses 5.2 0.0
Operating income 217.7 138.6
Reconciliation to Consolidated Net Income [Abstract]    
Operating income (loss) 217.7 138.6
Interest, net (61.5) (37.8)
Other income (expense), net 1.1 (11.1)
Income tax expense (53.0) (27.1)
Net income 104.3 62.6
Operating Segments    
Segment Reporting [Line Items]    
Net sales 1,474.6 899.9
Cost of goods sold 925.9 563.0
Gross profit 548.7 336.9
Selling, general and administrative expenses 246.0 118.4
Restructuring expenses 5.2  
Other expenses 18.9 4.4
Operating income 278.6 214.1
Reconciliation to Consolidated Net Income [Abstract]    
Operating income (loss) 278.6 214.1
General Corporate and R&D    
Segment Reporting [Line Items]    
Operating income (60.9) (75.5)
Reconciliation to Consolidated Net Income [Abstract]    
Operating income (loss) (60.9) (75.5)
Siding & Trim    
Segment Reporting [Line Items]    
Net sales 859.8 641.8
Siding & Trim | Operating Segments    
Segment Reporting [Line Items]    
Net sales 859.8 641.8
Cost of goods sold 525.7 401.3
Gross profit 334.1 240.5
Selling, general and administrative expenses 105.4 76.0
Restructuring expenses 0.0  
Other expenses 13.8 3.3
Operating income 214.9 161.2
Reconciliation to Consolidated Net Income [Abstract]    
Operating income (loss) 214.9 161.2
Deck, Rail & Accessories    
Segment Reporting [Line Items]    
Net sales 305.1 0.0
Deck, Rail & Accessories | Operating Segments    
Segment Reporting [Line Items]    
Net sales 305.1  
Cost of goods sold 208.2  
Gross profit 96.9  
Selling, general and administrative expenses 92.1  
Restructuring expenses 5.2  
Other expenses 2.9  
Operating income (3.3)  
Reconciliation to Consolidated Net Income [Abstract]    
Operating income (loss) (3.3)  
Australia & New Zealand    
Segment Reporting [Line Items]    
Net sales 153.3 121.6
Australia & New Zealand | Operating Segments    
Segment Reporting [Line Items]    
Net sales 153.3 121.6
Cost of goods sold 86.1 69.3
Gross profit 67.2 52.3
Selling, general and administrative expenses 19.1 14.2
Restructuring expenses 0.0  
Other expenses 1.3 0.3
Operating income 46.8 37.8
Reconciliation to Consolidated Net Income [Abstract]    
Operating income (loss) 46.8 37.8
Europe    
Segment Reporting [Line Items]    
Net sales 156.4 136.5
Europe | Operating Segments    
Segment Reporting [Line Items]    
Net sales 156.4 136.5
Cost of goods sold 105.9 92.4
Gross profit 50.5 44.1
Selling, general and administrative expenses 29.4 28.2
Restructuring expenses 0.0  
Other expenses 0.9 0.8
Operating income 20.2 15.1
Reconciliation to Consolidated Net Income [Abstract]    
Operating income (loss) $ 20.2 $ 15.1