Income Taxes (Textual) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Income tax payments	$ 10.8	$ 20.3	$ 24.9
Income tax refunds	1.2	0.8	0.5
Net expense in interest and penalties related to uncertain tax positions	0.4	0.2
Interest and penalties accrued	1.4	1.0
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	5.7
Settlement with IRS on examinations of 2011 and 2012 US Federal Tax Returns
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	$ 3.5