| **Inventories (Tables)**            | 12 Months Ended                                                                                                                                                                                                                      |
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| **Inventory Disclosure [Abstract]** |                                                                                                                                                                                                                                 |
| Components of Inventory             | The components of inventories were as follows: December 31,(in millions of dollars)2017 2016Raw materials$38.2 $30.3Work in process4.1 3.0Finished goods211.9 176.7Total inventories$254.2 $210.0 |

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| - References
No definition available.
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| - Definition
Tabular disclosure of the carrying amount as of the balance sheet date of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.
+ References
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