Accumulated other comprehensive income (loss) - Amounts in OCI (Details) - USD ($)
$ in Millions |
3 Months Ended |
9 Months Ended |
Sep. 30, 2026 |
Jun. 30, 2026 |
Mar. 31, 2026 |
Sep. 30, 2025 |
Jun. 30, 2025 |
Mar. 31, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
$ (25.8)
|
|
|
$ 12.1
|
|
|
$ (18.2)
|
$ 130.6
|
| Amounts Arising During the Current Period, Income Tax |
(1.6)
|
|
|
(3.0)
|
|
|
(4.9)
|
8.9
|
| Amounts Reclassified to Net Income (Loss), Pretax |
0.6
|
|
|
(2.8)
|
|
|
3.5
|
(2.7)
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
(0.4)
|
|
|
0.2
|
|
|
(0.7)
|
1.4
|
| Other comprehensive income (loss) |
(27.2)
|
$ 6.5
|
$ 0.4
|
6.5
|
$ 93.2
|
$ 38.5
|
(20.3)
|
138.2
|
| Cost of revenues |
1,040.3
|
|
|
990.4
|
|
|
3,085.9
|
2,906.6
|
| Selling, general and administrative expenses |
224.0
|
|
|
199.0
|
|
|
707.4
|
569.8
|
| Interest and other nonoperating expense |
24.7
|
|
|
(1.5)
|
|
|
28.1
|
(11.2)
|
| Interest expense |
66.0
|
|
|
63.4
|
|
|
192.4
|
181.8
|
| AOCI Attributable to Parent |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
(25.0)
|
|
|
12.7
|
|
|
(16.3)
|
126.6
|
| Amounts Arising During the Current Period, Income Tax |
(1.6)
|
|
|
(3.0)
|
|
|
(4.9)
|
8.9
|
| Amounts Reclassified to Net Income (Loss), Pretax |
0.6
|
|
|
(2.8)
|
|
|
3.5
|
(2.7)
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
(0.4)
|
|
|
0.2
|
|
|
(0.7)
|
1.4
|
| Other comprehensive income (loss) |
(26.4)
|
|
|
7.1
|
$ 89.3
|
$ 37.8
|
(18.4)
|
134.2
|
| Benefit plan adjustments |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
0.7
|
|
|
(1.4)
|
|
|
0.9
|
(9.2)
|
| Amounts Arising During the Current Period, Income Tax |
(0.2)
|
|
|
0.3
|
|
|
(1.2)
|
2.5
|
| Amounts Reclassified to Net Income (Loss), Pretax |
2.9
|
|
|
1.2
|
|
|
9.1
|
4.0
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
(0.8)
|
|
|
(0.3)
|
|
|
(2.3)
|
(1.0)
|
| Other comprehensive income (loss) |
2.6
|
|
|
(0.2)
|
|
|
6.5
|
(3.7)
|
| Foreign currency translation adjustments |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
(25.9)
|
|
|
11.2
|
|
|
(17.8)
|
134.7
|
| Amounts Arising During the Current Period, Income Tax |
(1.5)
|
|
|
(0.9)
|
|
|
(3.7)
|
10.0
|
| Amounts Reclassified to Net Income (Loss), Pretax |
(1.2)
|
|
|
(1.2)
|
|
|
(4.0)
|
(3.6)
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.2
|
|
|
0.2
|
|
|
0.9
|
0.8
|
| Other comprehensive income (loss) |
(28.4)
|
|
|
9.3
|
|
|
(24.6)
|
141.9
|
| Gains (losses) on available-for-sale securities |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
(0.1)
|
|
|
2.8
|
|
|
(0.9)
|
1.4
|
| Amounts Arising During the Current Period, Income Tax |
0.1
|
|
|
(2.4)
|
|
|
0.3
|
(3.7)
|
| Amounts Reclassified to Net Income (Loss), Pretax |
0.0
|
|
|
(1.1)
|
|
|
1.6
|
3.2
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.0
|
|
|
(0.1)
|
|
|
0.0
|
0.1
|
| Other comprehensive income (loss) |
0.0
|
|
|
(0.8)
|
|
|
1.0
|
1.0
|
| Gains (Losses) on Cash Flow Hedges |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
0.3
|
|
|
0.1
|
|
|
1.5
|
(0.3)
|
| Amounts Arising During the Current Period, Income Tax |
0.0
|
|
|
0.0
|
|
|
(0.3)
|
0.1
|
| Amounts Reclassified to Net Income (Loss), Pretax |
(1.1)
|
|
|
(1.7)
|
|
|
(3.2)
|
(6.3)
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.2
|
|
|
0.4
|
|
|
0.7
|
1.5
|
| Other comprehensive income (loss) |
(0.6)
|
|
|
(1.2)
|
|
|
(1.3)
|
(5.0)
|
| Gains (Losses) on Cash Flow Hedges | Reclassification out of accumulated other comprehensive income |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Interest expense |
(1.1)
|
|
|
(1.7)
|
|
|
(3.2)
|
(6.3)
|
| AOCI Attributable to Noncontrolling Interest |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
(0.8)
|
|
|
(0.6)
|
|
|
(1.9)
|
4.0
|
| Amounts Arising During the Current Period, Income Tax |
0.0
|
|
|
0.0
|
|
|
0.0
|
0.0
|
| Amounts Reclassified to Net Income (Loss), Pretax |
0.0
|
|
|
0.0
|
|
|
0.0
|
0.0
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.0
|
|
|
0.0
|
|
|
0.0
|
0.0
|
| Other comprehensive income (loss) |
(0.8)
|
|
|
(0.6)
|
|
|
(1.9)
|
4.0
|
| Foreign currency translation adjustments |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
(0.8)
|
|
|
(0.6)
|
|
|
(1.9)
|
4.0
|
| Amounts Arising During the Current Period, Income Tax |
0.0
|
|
|
0.0
|
|
|
0.0
|
0.0
|
| Amounts Reclassified to Net Income (Loss), Pretax |
0.0
|
|
|
0.0
|
|
|
0.0
|
0.0
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.0
|
|
|
0.0
|
|
|
0.0
|
0.0
|
| Other comprehensive income (loss) |
(0.8)
|
|
|
(0.6)
|
|
|
(1.9)
|
4.0
|
| Benefit plan adjustments |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
0.7
|
|
|
(1.4)
|
|
|
0.9
|
(9.2)
|
| Amounts Arising During the Current Period, Income Tax |
(0.2)
|
|
|
0.3
|
|
|
(1.2)
|
2.5
|
| Amounts Reclassified to Net Income (Loss), Pretax |
2.9
|
|
|
1.2
|
|
|
9.1
|
4.0
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
(0.8)
|
|
|
(0.3)
|
|
|
(2.3)
|
(1.0)
|
| Other comprehensive income (loss) |
2.6
|
|
|
(0.2)
|
|
|
6.5
|
(3.7)
|
| Benefit plan adjustments | Reclassification out of accumulated other comprehensive income |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Cost of revenues |
1.9
|
|
|
1.7
|
|
|
5.6
|
5.0
|
| Selling, general and administrative expenses |
0.6
|
|
|
0.4
|
|
|
1.7
|
1.4
|
| Interest and other nonoperating expense |
3.9
|
|
|
0.7
|
|
|
12.2
|
1.5
|
| Foreign currency translation adjustments |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
(26.7)
|
|
|
10.6
|
|
|
(19.7)
|
138.7
|
| Amounts Arising During the Current Period, Income Tax |
(1.5)
|
|
|
(0.9)
|
|
|
(3.7)
|
10.0
|
| Amounts Reclassified to Net Income (Loss), Pretax |
(1.2)
|
|
|
(1.2)
|
|
|
(4.0)
|
(3.6)
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.2
|
|
|
0.2
|
|
|
0.9
|
0.8
|
| Other comprehensive income (loss) |
(29.2)
|
|
|
8.7
|
|
|
(26.5)
|
145.9
|
| Gains (losses) on available-for-sale securities |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
(0.1)
|
|
|
2.8
|
|
|
(0.9)
|
1.4
|
| Amounts Arising During the Current Period, Income Tax |
0.1
|
|
|
(2.4)
|
|
|
0.3
|
(3.7)
|
| Amounts Reclassified to Net Income (Loss), Pretax |
0.0
|
|
|
(1.1)
|
|
|
1.6
|
3.2
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.0
|
|
|
(0.1)
|
|
|
0.0
|
0.1
|
| Other comprehensive income (loss) |
0.0
|
|
|
(0.8)
|
|
|
1.0
|
1.0
|
| Gains (losses) on cash flow hedges |
|
|
|
|
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
0.3
|
|
|
0.1
|
|
|
1.5
|
(0.3)
|
| Amounts Arising During the Current Period, Income Tax |
0.0
|
|
|
0.0
|
|
|
(0.3)
|
0.1
|
| Amounts Reclassified to Net Income (Loss), Pretax |
(1.1)
|
|
|
(1.7)
|
|
|
(3.2)
|
(6.3)
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.2
|
|
|
0.4
|
|
|
0.7
|
1.5
|
| Other comprehensive income (loss) |
$ (0.6)
|
|
|
$ (1.2)
|
|
|
$ (1.3)
|
$ (5.0)
|