Accumulated other comprehensive (loss) - Comprehensive Income (Loss) (Details) - USD ($)
$ in Millions |
3 Months Ended |
6 Months Ended |
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
$ 3.6
|
$ (5.2)
|
$ 29.3
|
$ 10.7
|
| Amounts Arising During the Current Period, Income Tax |
0.0
|
0.4
|
0.1
|
0.8
|
| Amounts Reclassified to Net Income (Loss), Pretax |
13.0
|
13.4
|
26.0
|
26.5
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
(4.4)
|
(4.6)
|
(8.9)
|
(8.8)
|
| Other comprehensive income |
12.2
|
4.0
|
46.5
|
29.2
|
| Cost of revenues |
628.9
|
596.1
|
1,239.2
|
1,185.0
|
| Selling, general and administrative expenses |
122.8
|
105.0
|
229.9
|
213.7
|
| Interest and other income (expense) |
(11.4)
|
(9.4)
|
(22.6)
|
(19.1)
|
| Other operating income (expense) |
5.9
|
6.2
|
6.0
|
6.9
|
| Benefit plan adjustments, Attributable to parent |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
(2.8)
|
(0.8)
|
(4.3)
|
(1.9)
|
| Amounts Arising During the Current Period, Income Tax |
0.2
|
0.2
|
0.4
|
0.5
|
| Amounts Reclassified to Net Income (Loss), Pretax |
13.2
|
12.6
|
25.8
|
24.9
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
(4.5)
|
(4.5)
|
(9.0)
|
(8.7)
|
| Other comprehensive income |
6.1
|
7.5
|
12.9
|
14.8
|
| Foreign currency translation adjustments, Attributable to parent |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
7.6
|
(3.5)
|
33.9
|
13.6
|
| 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 |
7.6
|
(3.5)
|
33.9
|
13.6
|
| Unrealized gains (losses) on available-for-sale securities, Attributable to parent |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
0.7
|
0.3
|
0.9
|
0.5
|
| Amounts Arising During the Current Period, Income Tax |
(0.2)
|
(0.2)
|
(0.3)
|
(0.2)
|
| Amounts Reclassified to Net Income (Loss), Pretax |
(0.2)
|
(0.5)
|
(0.2)
|
(0.5)
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.1
|
0.2
|
0.1
|
0.2
|
| Other comprehensive income |
0.4
|
(0.2)
|
0.5
|
0.0
|
| Gains (losses) on cash flow hedges, Attributable to parent |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
0.0
|
(1.2)
|
(0.2)
|
(2.2)
|
| Amounts Arising During the Current Period, Income Tax |
0.0
|
0.4
|
0.0
|
0.5
|
| Amounts Reclassified to Net Income (Loss), Pretax |
(0.1)
|
1.1
|
0.1
|
1.8
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.0
|
(0.3)
|
0.0
|
(0.3)
|
| Other comprehensive income |
(0.1)
|
0.0
|
(0.1)
|
(0.2)
|
| Gains (losses) on cash flow hedges, Attributable to parent | Reclassification out of accumulated other comprehensive income |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Interest and other income (expense) |
(0.1)
|
(0.1)
|
(0.1)
|
(0.2)
|
| Other operating income (expense) |
(0.2)
|
0.8
|
0.0
|
1.4
|
| AOCI Attributable to Parent |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
5.5
|
(5.2)
|
30.3
|
10.0
|
| Amounts Arising During the Current Period, Income Tax |
0.0
|
0.4
|
0.1
|
0.8
|
| Amounts Reclassified to Net Income (Loss), Pretax |
12.9
|
13.2
|
25.7
|
26.2
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
(4.4)
|
(4.6)
|
(8.9)
|
(8.8)
|
| Other comprehensive income |
14.0
|
3.8
|
47.2
|
28.2
|
| Benefit plan adjustments, Attributable to noncontrolling interest |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
0.0
|
0.0
|
0.0
|
0.0
|
| Amounts Arising During the Current Period, Income Tax |
0.0
|
0.0
|
0.0
|
0.0
|
| Amounts Reclassified to Net Income (Loss), Pretax |
0.1
|
0.2
|
0.3
|
0.3
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.0
|
0.0
|
0.0
|
0.0
|
| Other comprehensive income |
0.1
|
0.2
|
0.3
|
0.3
|
| Foreign currency translation adjustments, Attributable to noncontrolling interest |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
(1.9)
|
0.0
|
(1.0)
|
0.7
|
| 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 |
(1.9)
|
0.0
|
(1.0)
|
0.7
|
| AOCI Attributable to Noncontrolling Interest |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
(1.9)
|
0.0
|
(1.0)
|
0.7
|
| Amounts Arising During the Current Period, Income Tax |
0.0
|
0.0
|
0.0
|
0.0
|
| Amounts Reclassified to Net Income (Loss), Pretax |
0.1
|
0.2
|
0.3
|
0.3
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.0
|
0.0
|
0.0
|
0.0
|
| Other comprehensive income |
(1.8)
|
0.2
|
(0.7)
|
1.0
|
| Benefit plan adjustments |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
(2.8)
|
(0.8)
|
(4.3)
|
(1.9)
|
| Amounts Arising During the Current Period, Income Tax |
0.2
|
0.2
|
0.4
|
0.5
|
| Amounts Reclassified to Net Income (Loss), Pretax |
13.3
|
12.8
|
26.1
|
25.2
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
(4.5)
|
(4.5)
|
(9.0)
|
(8.7)
|
| Other comprehensive income |
6.2
|
7.7
|
13.2
|
15.1
|
| Benefit plan adjustments | Reclassification out of accumulated other comprehensive income |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Cost of revenues |
2.4
|
2.1
|
4.7
|
4.4
|
| Selling, general and administrative expenses |
0.5
|
0.6
|
1.1
|
1.1
|
| Interest and other income (expense) |
12.1
|
10.1
|
23.7
|
19.8
|
| Foreign currency translation adjustments |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
5.7
|
(3.5)
|
32.9
|
14.3
|
| 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 |
5.7
|
(3.5)
|
32.9
|
14.3
|
| Unrealized gains (losses) on available-for-sale securities(b) |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
0.7
|
0.3
|
0.9
|
0.5
|
| Amounts Arising During the Current Period, Income Tax |
(0.2)
|
(0.2)
|
(0.3)
|
(0.2)
|
| Amounts Reclassified to Net Income (Loss), Pretax |
(0.2)
|
(0.5)
|
(0.2)
|
(0.5)
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.1
|
0.2
|
0.1
|
0.2
|
| Other comprehensive income |
0.4
|
(0.2)
|
0.5
|
0.0
|
| Gains (losses) on cash flow hedges(c) |
|
|
|
|
| Other Comprehensive Income Loss [Line Items] |
|
|
|
|
| Amounts Arising During the Current Period, Pretax |
0.0
|
(1.2)
|
(0.2)
|
(2.2)
|
| Amounts Arising During the Current Period, Income Tax |
0.0
|
0.4
|
0.0
|
0.5
|
| Amounts Reclassified to Net Income (Loss), Pretax |
(0.1)
|
1.1
|
0.1
|
1.8
|
| Amounts Reclassified to Net Income (Loss), Income Tax |
0.0
|
(0.3)
|
0.0
|
(0.3)
|
| Other comprehensive income |
$ (0.1)
|
$ 0.0
|
$ (0.1)
|
$ (0.2)
|