Retirement Benefit Plans (Other Changes in Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income) (Details) - Other Postretirement Benefits Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Current year actuarial loss (gain)	$ 173	$ (44)
Amortization of actuarial loss	(44)	(64)
Amortization of prior service credit	50	52
Total recognized in other comprehensive loss	$ 179	$ (56)