Income Taxes - Uncertain Tax Positions (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Unrecognized tax benefits that would impact effective tax rate	$ 13.5
Interest related to unrecognized tax benefits	0.2
Cumulative interest accrued	1.6
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance as of January 1	9.4	7.7
Gross increases - tax positions in prior periods	0	1.5
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	3.5	0.2
Gross increases - tax positions in current period	(0.9)	0
Unrecognized Tax Benefits, Business Acquisition	23.8	0
Statute of limitation expirations	0.1	0
Balance as of December 31	$ 35.7	$ 9.4