v3.26.1
Earnings (Loss) Per Share (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
3 Months Ended 6 Months Ended
Feb. 03, 2026
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Numerator            
Net income (loss) attributable to Dauch   $ 1.0 $ 39.3 $ (99.3) $ 46.4  
Less: Net income attributable to participating securities   (0.1) (1.6) 0.0 (1.9)  
Net income (loss) attributable to common shareholders - Basic and Dilutive   $ 0.9 $ 37.7 $ (99.3) $ 44.5  
Denominators            
Basic - Weighted-average shares outstanding   245.0 123.9 222.7 123.2  
Basic - Less: Weighted-average participating securities   (7.8) (5.3) (7.3) (5.0)  
Basic - Weighted-average common shares outstanding   237.2 118.6 215.4 118.2  
Effect of dilutive securities - dilutive stock-based compensation   0.3 0.2 0.0 0.1  
Diluted - Adjusted weighted-average shares after assumed conversions   237.5 118.8 215.4 118.3  
Basic EPS   $ 0 $ 0.32 $ (0.46) $ 0.38  
Diluted EPS   $ 0 $ 0.32 $ (0.46) $ 0.38  
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount   0.3        
Common stock, shares authorized   375.0   375.0   150.0
Dowlais Group plc            
Denominators            
Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares 117.0          
Common stock, shares authorized 375.0