Employee Benefits (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Curtailment loss		$ 0
Special termination benefits		0
Defined Benefit Plan, Accumulated Benefit Obligation	121.8	101.0
Defined Contribution Plan, Cost Recognized	7.6	6.9	6.4
Active Employees [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Number of Employees Covered	62
Non-active Employees [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Number of Employees Covered	152
Employee Investment Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100.00%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	8.00%
Defined Contribution Plan Employer Discretionary Contribution Percent			2.00%
Closed Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match			100.00%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent			6.00%
Funded Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension Contributions	8.1
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year	4.0
Funded Pension Plan [Member] | Active Employees [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan Percentage Of Employees Covered	8.00%
Unfunded Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension Contributions	4.9
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year	4.4
Other Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Postretirement Health Care Benefits, Number of Eligible	39
Postretirement Health Care Benefits, Number of Employees Covered	36
Curtailment loss	1.4	0	0
Defined Benefit Plan, Curtailments	0.2	0	0
Special termination benefits	0	0	0
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year	0.3
Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year	0.2
Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), before Tax	(1.7)	(0.4)	(0.4)
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Curtailment loss	9.3		2.2
Defined Benefit Plan, Curtailments	8.2	0	2.2
Special termination benefits	1.9	0	0
Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year	4.1
Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), before Tax	$ (14.0)	$ (5.0)	$ (5.3)