Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Net income	$ 13.9us-gaap_NetIncomeLoss	$ 19.9us-gaap_NetIncomeLoss
Add: Loss from discontinued operations	0.1	0
Income from continuing operations	$ 14.0	$ 19.9
Weighted-average shares outstanding - basic	44.7	49.0
Effect of diluted securities attributable to stock-based payments	0.8	0.9
Weighted-average shares outstanding - diluted	45.5	49.9
Earnings per share – Basic:
Income from continuing operations, Basic	$ 0.31	$ 0.41
Loss from discontinued operations	$ 0.00	$ 0.00
Net income	$ 0.31us-gaap_EarningsPerShareBasic	$ 0.41us-gaap_EarningsPerShareBasic
Earnings per share – Diluted:
Income from continuing operations, Diluted	$ 0.31	$ 0.40
Loss from discontinued operations, Diluted	$ 0.00	$ 0.00
Net income	$ 0.31us-gaap_EarningsPerShareDiluted	$ 0.40us-gaap_EarningsPerShareDiluted

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount of income (loss) from a disposal group, net of income tax, reported as a separate component of income before extraordinary items after deduction or consideration of the amount allocable to noncontrolling interests. Includes, net of tax, income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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Per basic share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation and gain (loss) from the disposal of the discontinued operation.

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Per diluted share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation and gain (loss) from the disposal of the discontinued operation.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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