Pension and Other Post Retirement Benefits (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 Postretirement_Plan	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Number of Postretirement Plans	2
Pension and Other Post Retirement Details (Textual) [Abstract]
Collective bargaining agreement, beginning	2017-01
Defined Benefit Plan, Contributions by Employer	$ 1.8	$ 1.6	$ 1.6
Multiemployer plan contributions	5.00%
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of days notice upon which redemptions from real estate funds are available	45 days
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of days notice upon which redemptions from real estate funds are available	60 days
Defined Benefit Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Aggregate accumulated benefit obligation	475.8	426.3
Unrecognized net actuarial loss (gain)	11.3	14.9	9.9
Prior Service Credit	(1.0)	(1.0)	(1.0)
Defined benefit plan, estimated future employer contributions in next fiscal year	6.0
Pension and Other Post Retirement Details (Textual) [Abstract]
Defined Benefit Plan, Contributions by Employer	2.4	2.4
Other Post-retirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Unrecognized net actuarial loss (gain)	(0.1)	0	(0.1)
Prior Service Credit	(0.1)	(0.1)	(0.1)
Pension and Other Post Retirement Details (Textual) [Abstract]
Defined Benefit Plan, Contributions by Employer	$ 3.9	$ 3.3