Employee Benefits (Weighted-Average Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Qualified Pension Plan [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate	4.38%	3.69%
Rate of compensation increase	3.75%	3.75%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Equivalent single discount rate for benefit obligations	3.69%	4.18%	4.48%
Equivalent single discount rate for service cost	3.76%	4.29%	4.63%
Equivalent single discount rate for interest cost	3.42%	3.73%	3.88%
Expected long-term return on plan assets	6.75%	6.75%	6.75%
Rate of compensation increase	3.75%	3.75%	3.75%
Non-Qualified Retirement Plans [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate	4.30%	3.60%
Rate of compensation increase	3.75%	3.75%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Equivalent single discount rate for benefit obligations	3.58%	3.96%	4.20%
Equivalent single discount rate for service cost	3.79%	4.25%	4.59%
Equivalent single discount rate for interest cost	3.22%	3.36%	3.44%
Rate of compensation increase	3.75%	3.75%	3.75%