Employee Benefit Plans (Actuarial Assumptions Used for Accumulated Postretirement Benefit Obligation and Estimated Future Benefit Payments) (Details) (Other postretirement benefits, USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Other postretirement benefits
Defined Benefit Plans and Other Postretirement Benefit Plans
Discount rate (as a percentage)	4.01%	4.73%
Estimated future benefit payments 2015	$ 0.4
Estimated future benefit payments 2016	0.4
Estimated future benefit payments 2017	0.5
Estimated future benefit payments 2018	0.5
Estimated future benefit payments 2019	0.5
Estimated future benefit payments, Five fiscal years after 2019	$ 2.2