Employee Benefits (Narrative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2017 USD ($)
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions by Employer	$ 4.0
SERP [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions by Employer	1.8
Estimated Future Employer Contributions in Current Fiscal Year	0.2
Medical Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions by Employer	0.1
Estimated Future Employer Contributions in Current Fiscal Year	$ 0.1