v3.26.1
Accumulated Other Comprehensive Loss - Changes in accumulated other comprehensive loss (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Dec. 31, 2025
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Equity, Including Portion Attributable to Noncontrolling Interest $ 1,145.7 $ 1,145.7 $ 1,145.3 $ 1,257.8 $ 1,299.7 $ 1,307.2
Changes in accumulated other comprehensive loss            
Other comprehensive income, net of tax, before reclassifications 16.1          
Amounts reclassified from AOCI, net of tax expense of $1.3, $—, and $1.3 (3.9)          
Reclassification from AOCI, Current Period, Tax 1.3          
Other comprehensive income 12.2          
Unrealized gains/(losses) on derivative financial instruments            
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Equity, Including Portion Attributable to Noncontrolling Interest 9.3   (2.8)      
Changes in accumulated other comprehensive loss            
Other comprehensive income, net of tax, before reclassifications 16.1          
Amounts reclassified from AOCI, net of tax expense of $1.3, $—, and $1.3 (4.0)          
Reclassification from AOCI, Current Period, Tax 1.3          
Other comprehensive income 12.1          
Net actuarial gains/(losses) of defined benefit plans            
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Equity, Including Portion Attributable to Noncontrolling Interest (1.3)   (1.4)      
Changes in accumulated other comprehensive loss            
Other comprehensive income, net of tax, before reclassifications 0.0          
Amounts reclassified from AOCI, net of tax expense of $1.3, $—, and $1.3 0.1          
Reclassification from AOCI, Current Period, Tax 0.0          
Other comprehensive income 0.1          
Accumulated other comprehensive income (loss)            
Accumulated Other Comprehensive Income (Loss) [Line Items]            
Equity, Including Portion Attributable to Noncontrolling Interest $ 8.0 $ 1.0 $ (4.2) $ (4.2) $ (4.2) $ (4.2)