Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$ 84.1us-gaap_NetIncomeLoss	$ 77.8us-gaap_NetIncomeLoss	$ 66.9us-gaap_NetIncomeLoss
Changes in cumulative translation adjustment	(18.0)	1.2	7.2
Changes in unrealized gains/(losses) on derivative instruments, net of tax of $0.0 million, $0.0 million and $0.0 million, respectively	0	(0.1)	(0.1)
Amortization of prior service credit, net of tax of $0.3 million, $0.3 million and $0.3 million, respectively	(1.0)	(1.0)	(1.0)
Amortization of actuarial net losses, net of tax of $(1.1) million, $(1.4) million and $(0.8) million, respectively	4.3	4.8	2.4
Actuarial net gains/(losses) arising during the year, net of tax of $(13.9) million, $1.8 million and $17.8 million, respectively	54.7	(6.7)	(58.5)
Total comprehensive income	$ 124.1us-gaap_ComprehensiveIncomeNetOfTax	$ 76.0us-gaap_ComprehensiveIncomeNetOfTax	$ 16.9us-gaap_ComprehensiveIncomeNetOfTax

Other Comprehensive Income Loss Net Actuarial Gain Loss Net Of Tax

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) related to pension and other postretirement benefit plans.

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Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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