v3.25.4
Earnings per share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Net (loss)/earnings $ (3.4) $ 22.3
Weighted average number of shares outstanding, basic (in shares) 68.4 72.0
Basic net (loss)/earnings per common share (in dollars per share) $ (0.05) $ 0.31
Weighted average number of shares outstanding, diluted (in shares) 68.4 73.2
Diluted net (loss)/earnings per common share- continuing operations (in dollars per share) $ (0.05) $ 0.30
Performance Shares    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Effect of dilutive performance shares (shares) 0.0 0.7
Restricted Stock Equivalents    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Effect of dilutive performance shares (shares) 0.0 0.5