Pension Plans (Schedule of Weighted Average Assumptions Used to Determine Pension Benefit Obligations) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Type [Extensible List]	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember
Defined Benefit Plan, Sponsor Location [Extensible List]	country:US	country:US
Cash balance interest crediting rate	3.00%	3.50%	3.50%
Expected return on plan assets	4.75%
Qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Type [Extensible List]	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember
Defined Benefit Plan, Sponsor Location [Extensible List]	country:US	country:US	country:US
Discount rate	3.00%	3.75%	4.50%
Discount rate	3.75%	4.50%	3.88%
Expected return on plan assets	4.75%	5.50%	4.75%
Cash balance interest crediting rate	3.50%	3.50%	3.50%
Nonqualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Type [Extensible List]	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember
Defined Benefit Plan, Sponsor Location [Extensible List]	country:US	country:US	country:US
Discount rate	2.88%	4.00%	4.50%
Discount rate	4.00%	4.50%	3.88%