Retirement Benefit Plans (Net Periodic Benefit Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 1,002	$ 1,285
Expected return on plan assets	(2,568)	(2,435)
Amortization of actuarial loss (gain)	718	597
Amortization of prior service cost	59	58
Net periodic pension income	(789)	(495)
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	13	21
Interest cost	27	52
Amortization of actuarial loss (gain)	19	(1)
Amortization of prior service cost	(54)	(59)
Amortization of curtailment	0	(31)
Net periodic pension income	$ 5	$ (18)