Retirement Benefit Plans (Components of Net Periodic (Benefits) Cost) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Total recognized in other comprehensive income	$ (28,191)	$ 13,325	$ 24,139
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	7,707	7,916	11,438
Interest cost	$ 24,047	$ 23,854	$ 14,639
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense
Expected return on plan assets	$ (47,626)	$ (44,710)	$ (46,615)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense
Amortization of net (gain) loss/ prior service cost	$ 5,687	$ 7,643	$ 2,830
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense
Net periodic benefit cost	$ (10,185)	$ (5,297)	$ (17,708)
Net (loss) gain recognized during the year	(5,687)	(7,643)	(2,830)
Net actuarial loss (gain)	(26,038)	13,449	29,952
Total recognized in other comprehensive income	(31,725)	5,806	27,122
Total recognized in net periodic benefit cost and other comprehensive income	$ (41,910)	$ 509	$ 9,414
Discount rate for benefit obligations	5.62%	4.83%	5.00%
Discount rate for net periodic benefit cost	4.83%	5.00%	2.77%
Expected long-term return on plan assets	6.50%	6.50%	5.50%
Pension Benefits [Member] | Graded Scale, 7.25% At Age 20 [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	7.25%	7.25%	7.25%
Pension Benefits [Member] | Graded Scale, 2.25% At Age 60 [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	2.25%	2.25%	2.25%
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 31	$ 34	$ 59
Interest cost	$ 578	$ 622	$ 375
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense
Amortization of net (gain) loss/ prior service cost	$ (799)	$ (843)	$ (650)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense	Payroll Taxes Healthcare Costs Pension And Other Postretirement Benefit Expense
Net periodic benefit cost	$ (190)	$ (187)	$ (216)
Net (loss) gain recognized during the year	799	843	650
Net actuarial loss (gain)	(2,371)	92	(5,906)
Total recognized in other comprehensive income	(1,572)	935	(5,256)
Total recognized in net periodic benefit cost and other comprehensive income	$ (1,762)	$ 748	$ (5,472)
Discount rate for benefit obligations	5.56%	4.81%	4.98%
Discount rate for net periodic benefit cost	4.81%	4.98%	2.32%