Related Parties (Details) (Director [Member], USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Related Party Transaction [Line Items]
Amounts invested in Defined Contribution Plan Mutual Fund Managed by a Directors Investment Advisory Firm	$ 22.6
Amounts invested in Defined Contribution Plan Mutual Fund Managed by a Directors Investment Advisory Firm Percentage of Total Defined Contribution Plan Investments	6.40%
Trinity [Member]
Related Party Transaction [Line Items]
Amount of assets being managed by FS&C	165.8
Investment expenses	0.3	0.3
Pension Plan, Defined Benefit [Member]
Related Party Transaction [Line Items]
Investment expenses	0.3	0.2
Pension Plan, Defined Benefit [Member]
Related Party Transaction [Line Items]
Amount of assets being managed by FS&C	$ 157.8