Benefit Plans (Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension Benefits [Member]
Weighted average assumptions used in net periodic benefit cost:
Discount rate	4.08%	4.50%	3.99%
Rate of compensation increase	4.07%	4.29%	4.24%
Long-term rate of return on assets	6.84%	7.01%	7.12%
Weighted average assumptions used in benefit obligations:
Discount rate	4.22%	3.96%
Rate of compensation increase	4.07%	4.14%
Other Retirement Benefits [Member]
Weighted average assumptions used in net periodic benefit cost:
Discount rate	3.90%	4.55%	3.50%
Weighted average assumptions used in benefit obligations:
Discount rate	4.30%	3.90%