Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Jul. 17, 2013
Income Tax Contingency [Line Items]
Effective tax rates (as a percent)	28.80%	27.50%
U.S. statutory rate (as a percent)	35.00%	35.00%
Income Tax Expense (Benefit)	$ 25.0	$ 30.9
Tax Assessment Year 2007 to 2009 | Internal Revenue Service (IRS)
Income Tax Contingency [Line Items]
Total tax assessment			73.8
Tax assessments related to disallowed deductions			$ 60.2