v3.26.1
Accumulated other comprehensive income (loss) - Amounts in OCI (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Other Comprehensive Income Loss [Line Items]    
Amounts Arising During the Current Period, Pretax $ 1.2 $ 36.3
Amounts Arising During the Current Period, Income Tax (3.0) 3.7
Amounts Reclassified to Net Income (Loss), Pretax 2.2 (2.3)
Amounts Reclassified to Net Income (Loss), Income Tax 0.0 0.8
Other comprehensive income (loss) 0.4 38.5
Cost of revenues 1,019.4 939.5
Selling, general and administrative expenses 250.8 186.3
Interest and other nonoperating expense 0.9 (7.9)
Interest expense 63.5 57.5
AOCI Attributable to Parent    
Other Comprehensive Income Loss [Line Items]    
Amounts Arising During the Current Period, Pretax 2.2 35.6
Amounts Arising During the Current Period, Income Tax (3.0) 3.7
Amounts Reclassified to Net Income (Loss), Pretax 2.2 (2.3)
Amounts Reclassified to Net Income (Loss), Income Tax 0.0 0.8
Other comprehensive income (loss) 1.4 37.8
Benefit plan adjustments    
Other Comprehensive Income Loss [Line Items]    
Amounts Arising During the Current Period, Pretax 0.4 (3.4)
Amounts Arising During the Current Period, Income Tax (1.0) 0.9
Amounts Reclassified to Net Income (Loss), Pretax 3.2 1.2
Amounts Reclassified to Net Income (Loss), Income Tax (0.8) (0.3)
Other comprehensive income (loss) 1.8 (1.6)
Foreign currency translation adjustments    
Other Comprehensive Income Loss [Line Items]    
Amounts Arising During the Current Period, Pretax 2.1 38.7
Amounts Arising During the Current Period, Income Tax (2.2) 2.9
Amounts Reclassified to Net Income (Loss), Pretax (1.5) (1.2)
Amounts Reclassified to Net Income (Loss), Income Tax 0.4 0.3
Other comprehensive income (loss) (1.2) 40.7
Gains (losses) on available-for-sale securities    
Other Comprehensive Income Loss [Line Items]    
Amounts Arising During the Current Period, Pretax (1.0) 0.4
Amounts Arising During the Current Period, Income Tax 0.4 (0.1)
Amounts Reclassified to Net Income (Loss), Pretax 1.6 0.2
Amounts Reclassified to Net Income (Loss), Income Tax 0.1 0.2
Other comprehensive income (loss) 1.1 0.7
Gains (Losses) on Cash Flow Hedges    
Other Comprehensive Income Loss [Line Items]    
Amounts Arising During the Current Period, Pretax 0.7 (0.1)
Amounts Arising During the Current Period, Income Tax (0.2) 0.0
Amounts Reclassified to Net Income (Loss), Pretax (1.1) (2.5)
Amounts Reclassified to Net Income (Loss), Income Tax 0.3 0.6
Other comprehensive income (loss) (0.3) (2.0)
Gains (Losses) on Cash Flow Hedges | Reclassification out of accumulated other comprehensive income    
Other Comprehensive Income Loss [Line Items]    
Interest expense (1.1) (2.5)
AOCI Attributable to Noncontrolling Interest    
Other Comprehensive Income Loss [Line Items]    
Amounts Arising During the Current Period, Pretax (1.0) 0.7
Amounts Arising During the Current Period, Income Tax 0.0 0.0
Amounts Reclassified to Net Income (Loss), Pretax 0.0 0.0
Amounts Reclassified to Net Income (Loss), Income Tax 0.0 0.0
Other comprehensive income (loss) (1.0) 0.7
Foreign currency translation adjustments    
Other Comprehensive Income Loss [Line Items]    
Amounts Arising During the Current Period, Pretax (1.0) 0.7
Amounts Arising During the Current Period, Income Tax 0.0 0.0
Amounts Reclassified to Net Income (Loss), Pretax 0.0 0.0
Amounts Reclassified to Net Income (Loss), Income Tax 0.0 0.0
Other comprehensive income (loss) (1.0) 0.7
Benefit plan adjustments    
Other Comprehensive Income Loss [Line Items]    
Amounts Arising During the Current Period, Pretax 0.4 (3.4)
Amounts Arising During the Current Period, Income Tax (1.0) 0.9
Amounts Reclassified to Net Income (Loss), Pretax 3.2 1.2
Amounts Reclassified to Net Income (Loss), Income Tax (0.8) (0.3)
Other comprehensive income (loss) 1.8 (1.6)
Benefit plan adjustments | Reclassification out of accumulated other comprehensive income    
Other Comprehensive Income Loss [Line Items]    
Cost of revenues 1.9 1.6
Selling, general and administrative expenses 0.6 0.5
Interest and other nonoperating expense 4.2 0.1
Foreign currency translation adjustments    
Other Comprehensive Income Loss [Line Items]    
Amounts Arising During the Current Period, Pretax 1.1 39.4
Amounts Arising During the Current Period, Income Tax (2.2) 2.9
Amounts Reclassified to Net Income (Loss), Pretax (1.5) (1.2)
Amounts Reclassified to Net Income (Loss), Income Tax 0.4 0.3
Other comprehensive income (loss) (2.2) 41.4
Gains (losses) on available-for-sale securities    
Other Comprehensive Income Loss [Line Items]    
Amounts Arising During the Current Period, Pretax (1.0) 0.4
Amounts Arising During the Current Period, Income Tax 0.4 (0.1)
Amounts Reclassified to Net Income (Loss), Pretax 1.6 0.2
Amounts Reclassified to Net Income (Loss), Income Tax 0.1 0.2
Other comprehensive income (loss) 1.1 0.7
Gains (losses) on cash flow hedges    
Other Comprehensive Income Loss [Line Items]    
Amounts Arising During the Current Period, Pretax 0.7 (0.1)
Amounts Arising During the Current Period, Income Tax (0.2) 0.0
Amounts Reclassified to Net Income (Loss), Pretax (1.1) (2.5)
Amounts Reclassified to Net Income (Loss), Income Tax 0.3 0.6
Other comprehensive income (loss) $ (0.3) $ (2.0)