Pension Plans (Summary of Estimated Benefit Payments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Type [Extensible List]	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember
Defined Benefit Plan, Sponsor Location [Extensible List]	us-gaap:DomesticPlanMember	us-gaap:DomesticPlanMember	us-gaap:DomesticPlanMember
Qualified Plan [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Type [Extensible List]	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember
Defined Benefit Plan, Sponsor Location [Extensible List]	us-gaap:DomesticPlanMember	us-gaap:DomesticPlanMember	us-gaap:DomesticPlanMember
2024	$ 36.7
2025	35.0
2026	33.6
2027	32.9
2028	30.9
2029-2033	$ 131.7
Nonqualified Plan [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Type [Extensible List]	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember	us-gaap:PensionPlansDefinedBenefitMember
Defined Benefit Plan, Sponsor Location [Extensible List]	us-gaap:DomesticPlanMember	us-gaap:DomesticPlanMember	us-gaap:DomesticPlanMember
2024	$ 2.7
2025	2.6
2026	2.5
2027	2.4
2028	2.3
2029-2033	$ 9.4