Supplemental Disclosures (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for doubtful accounts
Interest paid	$ 6.0us-gaap_InterestPaid	$ 2.5us-gaap_InterestPaid	$ 2.6us-gaap_InterestPaid
Income taxes paid	17.6us-gaap_IncomeTaxesPaidNet	69.8us-gaap_IncomeTaxesPaidNet	33.7us-gaap_IncomeTaxesPaidNet
Capital spending in accounts payable and accrued liabilities	2.5	3.6	4.3
Allowance for Doubtful Accounts [Member]
Allowance for doubtful accounts
Beginning balance	0.4	0.7	0.7
Bad debt expense	0.3	0	0.1
Write-offs and discounts	(0.4)	(0.2)	(0.1)
Currency translation	0	(0.1)	0
Ending balance	$ 0.3	$ 0.4	$ 0.7

For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible.

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