Comprehensive Income - Schedule of Components of Other Comprehensive Income and Income Tax Expense Allocated to Each Component (Details) - USD ($)
$ in Millions |
12 Months Ended |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
| Accumulated Other Comprehensive Income Loss [Line Items] |
|
|
|
| Other comprehensive (loss) income, Before Tax Amount |
$ 11.8
|
$ 38.4
|
$ (287.4)
|
| Other comprehensive (loss) income, Income Tax Expense |
4.8
|
18.4
|
(114.6)
|
| Other comprehensive income (loss), net of tax |
7.0
|
20.0
|
(172.8)
|
| Translation adjustments |
|
|
|
| Accumulated Other Comprehensive Income Loss [Line Items] |
|
|
|
| Other comprehensive (loss) income, Before Tax Amount |
(0.1)
|
(7.5)
|
(2.9)
|
| Other comprehensive (loss) income, Income Tax Expense |
0.0
|
0.0
|
0.0
|
| Other comprehensive income (loss), net of tax |
(0.1)
|
(7.5)
|
(2.9)
|
| Adjustment for Net Periodic Pension Plan and Other Postretirement Benefits Plan Cost |
|
|
|
| Accumulated Other Comprehensive Income Loss [Line Items] |
|
|
|
| Other comprehensive (loss) income, Before Tax Amount |
11.9
|
45.9
|
(284.5)
|
| Other comprehensive (loss) income, Income Tax Expense |
4.8
|
18.4
|
(114.6)
|
| Other comprehensive income (loss), net of tax |
$ 7.1
|
$ 27.5
|
$ (169.9)
|