Summary of Significant Accounting Policies - Components of Accumulated Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Accumulated pension and OPEB liability adjustments, net of income tax impact of $21.0 million and $16.6 million at December 31, 2014 and 2013, respectively	$ (38.4)	$ (30.1)
Accumulated unrealized loss on derivative instruments, net of income tax impact of $0 and $0.3 million at December 31, 2014 and 2013, respectively	(8.3)	(8.1)
Accumulated unrealized foreign currency translation adjustments	(29.8)	33.2
Accumulated other comprehensive loss	(76.5)	(5.0)
Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Postretirement Plans, Tax	21.0	16.6
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Tax	$ 0	$ 0.3

Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

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The total of net gain (loss), prior service cost (credit), and transition assets (obligations), as well as minimum pension liability if still remaining, included in accumulated other comprehensive income associated with a defined benefit pension or other postretirement plan(s) because they have yet to be recognized as components of net periodic benefit cost.

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- Definition

Accumulated adjustment, net of tax, that results from the process of translating subsidiary financial statements and foreign equity investments into the reporting currency from the functional currency of the reporting entity, net of reclassification of realized foreign currency translation gains or losses.

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- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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