Savings Plans, Pension Plans and Other Postretirement Employee Benefits (Narrative) (Details) - USD ($)	1 Months Ended	12 Months Ended
	Feb. 29, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Mar. 31, 2022	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Contributions by employer		$ 4,200,000	$ 4,000,000.0	$ 3,600,000
Accumulated benefit obligation		223,700,000	374,700,000
Funding of pension and other postretirement benefit plans		5,065,000	9,044,000	$ 10,004,000
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Investments in Level 3		0	$ 0
Qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan and other postretirement employee benefit, estimated payments in next fiscal year		$ 0
Management Deferred Compensation Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Annual incentive plan, employee permitted minimum defer percentage		50.00%
Annual incentive plan, employee permitted maximum defer percentage		100.00%
Management Deferred Compensation Plan [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Basic salary defer percentage		50.00%
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Change in monthly retirement benefit amount	$ 0	$ 0
Non-cash pretax settlement charge	43,000,000.0	$ 14,200,000
Discount rate used to measure projected benefit obligations for qualified pension plans		5.60%	3.00%
Pension plan and other postretirement employee benefit, estimated payments in next fiscal year		$ 16,141,000
Pension Plans [Member] | Qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate used to measure projected benefit obligations for qualified pension plans		3.95%	3.00%	2.95%		3.40%
Pension Plans [Member] | Qualified Plan [Member] | Funded with Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Transfer of outstanding pension benefit obligation related to qualified pension plans to insurance company	$ 101,100,000				$ 75,600,000
Pension Plans [Member] | Nonqualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan and other postretirement employee benefit, estimated payments in next fiscal year		$ 2,500,000
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate used to measure projected benefit obligations for qualified pension plans		5.55%	2.95%
Pension plan and other postretirement employee benefit, estimated payments in next fiscal year		$ 2,409,000
Defined Benefit Plan, Assumption Health Care Cost Trend Rate for Next Fiscal Year		4.00%
Other Postretirement Benefit Plans [Member] | Nonqualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan and other postretirement employee benefit, estimated payments in next fiscal year		$ 2,400,000
Other Postretirement Benefit Plans [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate assumed for next fiscal year		9.81%
Other Postretirement Benefit Plans [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate assumed for next fiscal year		11.77%