Retirement Plans (Weighted-average rate assumptions of the Pension and Postretirement Plans) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate used in determining benefit obligation	4.55%	4.15%	5.00%
Discount rate used in determining expense	4.15%	5.00%	4.08%
Expected long-term return on Pension Plan assets	6.75%	7.00%	7.00%
Rate of compensation increase used in determining benefit obligation	3.50%	3.50%	3.50%
Rate of compensation increase used in determining pension expense	3.50%	3.50%	3.50%
Year 1 increase in cost of postretirement benefits	0.00%	0.00%	0.00%
Supplemental Employee Retirement Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate used in determining benefit obligation	4.51%	4.07%	4.87%
Postretirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate used in determining benefit obligation	4.23%	3.75%	4.27%
Discount rate used in determining expense	3.75%	4.27%	4.08%
Expected long-term return on Pension Plan assets	0.00%	0.00%	0.00%
Rate of compensation increase used in determining benefit obligation	0.00%	0.00%	0.00%
Rate of compensation increase used in determining pension expense	0.00%	0.00%	0.00%
Year 1 increase in cost of postretirement benefits	7.50%	8.00%	8.50%