Income Taxes (Unrecognized Tax Benefits Reconciliation) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits at beginning of year	$ 55.6us-gaap_UnrecognizedTaxBenefits	$ 57.3us-gaap_UnrecognizedTaxBenefits	$ 47.1us-gaap_UnrecognizedTaxBenefits
Increases in unrecognized tax benefits related to the current year	25.5	4.4	2.4
Increases in unrecognized tax benefits related to prior years	0	0	8.0
Decreases in unrecognized tax benefits related to a prior year	(17.5)	(0.2)	(0.2)
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	0	(1.9)	0
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	(2.1)	(4.0)	0
Gross unrecognized tax benefits at end of year	61.5us-gaap_UnrecognizedTaxBenefits	55.6us-gaap_UnrecognizedTaxBenefits	57.3us-gaap_UnrecognizedTaxBenefits
Liability for unrecognized tax benefits	64.9	59.3
Unrecognized tax benefits that if recognized would impact effective tax rate	19.6	9.7
Unrecognized tax benefits that would impact deferred tax asset	45.3	49.6
Unrecognized tax benefits, interest recorded	(1.9)	(0.3)	1.7
Unrecognized tax benefits, interest accruals	1.8	3.7	4.1
Decrease due to examinations settlements [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Change in unrecognized tax benefits	7.2
IncreaseDueToUtilizationOfNOLCarryforwards [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Change in unrecognized tax benefits	$ 2.6

Unrecognized Tax Benefits that Would Impact Deferred Tax Asset

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The noncurrent portion of the amount recognized for uncertain tax positions as of the balance sheet date.

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The amount of the unrecognized tax benefit of a position taken for which it is reasonably possible that the total amount thereof will significantly increase or decrease within twelve months of the balance sheet date.

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Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of interest expense accrued for an underpayment of income taxes.

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Amount of interest expense for an underpayment of income taxes.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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