Retirement Benefit Plans (Net Periodic Benefit Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 1,639	$ 1,105
Expected return on plan assets	(2,751)	(2,707)
Amortization of actuarial loss	51	543
Amortization of prior service credit	58	58
Settlements	1,815	0
Net periodic pension expense (income)	812	(1,001)
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	77	38
Amortization of actuarial loss	44	64
Amortization of prior service credit	(50)	(52)
Service cost	7	12
Net periodic pension expense (income)	$ 78	$ 62