Defined Benefit Pension Plans (Weighted-Average Assumptions Used) (Details)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Qualified Pension Plan [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Equivalent single discount rate for benefit obligations	2.71%	3.42%
Equivalent single discount rate for service cost	2.86%	3.54%
Equivalent single discount rate for interest cost	2.16%	3.07%
Expected long-term return on plan assets	5.75%	5.75%
Rate of compensation increase	3.75%	3.75%
Non-Qualified Retirement Plans [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Equivalent single discount rate for benefit obligations	2.51%	3.30%
Equivalent single discount rate for service cost	2.94%	3.62%
Equivalent single discount rate for interest cost	1.97%	2.93%
Rate of compensation increase	3.75%	3.75%