Accumulated other comprehensive income (loss) - Amounts in OCI (Details) - USD ($) $ in Millions | 3 Months Ended |
Mar. 31, 2022 | Mar. 31, 2021 |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | $ 31.1 | $ (53.1) |
Amounts Arising During the Current Period, Income Tax | 1.9 | 0.7 |
Amounts Reclassified to Net Income (Loss), Pretax | 23.2 | 12.8 |
Amounts Reclassified to Net Income (Loss), Income Tax | (6.8) | (3.2) |
Other comprehensive income (loss) | 49.4 | (42.8) |
Cost of revenues | 839.7 | 758.8 |
Selling, general and administrative expenses | 171.6 | 154.3 |
Interest and other income (expense) | (1.3) | (5.5) |
Other operating income (expense) | (0.3) | (2.9) |
Interest expense | 27.9 | 27.2 |
Benefit plan adjustments | | |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | (0.9) | (17.3) |
Amounts Arising During the Current Period, Income Tax | 0.2 | 4.1 |
Amounts Reclassified to Net Income (Loss), Pretax | 10.1 | 16.1 |
Amounts Reclassified to Net Income (Loss), Income Tax | (2.4) | (4.6) |
Other comprehensive income (loss) | 7 | (1.7) |
Foreign currency translation adjustments | | |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | 35.1 | (44.2) |
Amounts Arising During the Current Period, Income Tax | (0.4) | 0 |
Amounts Reclassified to Net Income (Loss), Pretax | (1.5) | 0 |
Amounts Reclassified to Net Income (Loss), Income Tax | 0.4 | 0 |
Other comprehensive income (loss) | 33.6 | (44.2) |
Unrealized losses on available-for-sale securities | | |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | (0.4) | |
Amounts Arising During the Current Period, Income Tax | 0 | |
Amounts Reclassified to Net Income (Loss), Pretax | 0 | |
Amounts Reclassified to Net Income (Loss), Income Tax | 0 | |
Other comprehensive income (loss) | (0.4) | |
Gains (losses) on cash flow hedges | | |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | (1.2) | 10.5 |
Amounts Arising During the Current Period, Income Tax | 2.1 | (3.4) |
Amounts Reclassified to Net Income (Loss), Pretax | 14.6 | (3.3) |
Amounts Reclassified to Net Income (Loss), Income Tax | (4.8) | 1.4 |
Other comprehensive income (loss) | 10.7 | 5.2 |
Gains (losses) on cash flow hedges | Reclassification out of accumulated other comprehensive income | | |
Other Comprehensive Income Loss [Line Items] | | |
Other operating income (expense) | 11.8 | 6.1 |
Interest expense | 2.8 | 2.7 |
AOCI Attributable to Parent | | |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | 32.6 | (51) |
Amounts Arising During the Current Period, Income Tax | 1.9 | 0.7 |
Amounts Reclassified to Net Income (Loss), Pretax | 23.2 | 12.8 |
Amounts Reclassified to Net Income (Loss), Income Tax | (6.8) | (3.2) |
Other comprehensive income (loss) | 50.9 | (40.7) |
Benefit plan adjustments | | |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | | (0.3) |
Other comprehensive income (loss) | | (0.3) |
Foreign currency translation adjustments | | |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | (1.5) | (1.8) |
Amounts Arising During the Current Period, Income Tax | 0 | 0 |
Amounts Reclassified to Net Income (Loss), Pretax | 0 | 0 |
Amounts Reclassified to Net Income (Loss), Income Tax | 0 | 0 |
Other comprehensive income (loss) | (1.5) | (1.8) |
AOCI Attributable to Noncontrolling Interest | | |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | (1.5) | (2.1) |
Amounts Arising During the Current Period, Income Tax | 0 | 0 |
Amounts Reclassified to Net Income (Loss), Pretax | 0 | 0 |
Amounts Reclassified to Net Income (Loss), Income Tax | 0 | 0 |
Other comprehensive income (loss) | (1.5) | (2.1) |
Benefit plan adjustments(a) | | |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | (0.9) | (17.6) |
Amounts Arising During the Current Period, Income Tax | 0.2 | 4.1 |
Amounts Reclassified to Net Income (Loss), Pretax | 10.1 | 16.1 |
Amounts Reclassified to Net Income (Loss), Income Tax | (2.4) | (4.6) |
Other comprehensive income (loss) | 7 | (2) |
Benefit plan adjustments(a) | Reclassification out of accumulated other comprehensive income | | |
Other Comprehensive Income Loss [Line Items] | | |
Cost of revenues | 1.6 | 1.7 |
Selling, general and administrative expenses | 0.5 | 0.5 |
Interest and other income (expense) | 4.8 | 9.6 |
Foreign currency translation adjustments | | |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | 33.6 | (46) |
Amounts Arising During the Current Period, Income Tax | (0.4) | 0 |
Amounts Reclassified to Net Income (Loss), Pretax | (1.5) | 0 |
Amounts Reclassified to Net Income (Loss), Income Tax | 0.4 | 0 |
Other comprehensive income (loss) | 32.1 | (46) |
Unrealized losses on available-for-sale securities(c) | | |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | (0.4) | |
Amounts Arising During the Current Period, Income Tax | 0 | |
Amounts Reclassified to Net Income (Loss), Pretax | 0 | |
Amounts Reclassified to Net Income (Loss), Income Tax | 0 | |
Other comprehensive income (loss) | (0.4) | |
Gains (losses) on cash flow hedges(d) | | |
Other Comprehensive Income Loss [Line Items] | | |
Amounts Arising During the Current Period, Pretax | (1.2) | 10.5 |
Amounts Arising During the Current Period, Income Tax | 2.1 | (3.4) |
Amounts Reclassified to Net Income (Loss), Pretax | 14.6 | (3.3) |
Amounts Reclassified to Net Income (Loss), Income Tax | (4.8) | 1.4 |
Other comprehensive income (loss) | $ 10.7 | $ 5.2 |