Income Taxes (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Income Tax Examination [Line Items]
Deferred income tax expense (benefit)		$ 41.7
Net deferred tax liability	1.4	2.1
Income tax receivable	4.5	20.1
Income tax refund, net	7.6
Net operating loss carryforwards	697.5
Estimated amount of net operating loss carryforwards that will not be utilized	234.7
Foreign tax credit carryforwards, subject to expriration	13.5
Valuation allowance	494.5	454.1
Unrecognized tax benefits that would impact effective tax rate	11.6	27.6
Unrecognized Tax Benefits, Interest on Income Taxes Expense	1.1	1.4
Interest accrual reversal	11.2	2.6
Interest accrued net reduction	10.1	1.2
Total amount of interest accrued for uncertain tax positions	4.4	14.5
Amount by which unrecognized tax benefits may decrease over the next 12 months	5.9
State and Foreign Tax Authority [Member]
Income Tax Examination [Line Items]
Tax paid to settle audits of tax years 2001-08 for certain subsidiaries	1.6
Interest paid to settle audits of tax years 2001-08 for certain subsidiaries	$ 7.8