Retirement Benefit Plans (Summary of Components of Accumulated Other Comprehensive Loss Related to Pensions and Postretirement Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	$ 41,792	$ 57,902
Deferred tax benefit	8,636	12,881
Amounts included in accumulated AOCL, net of tax	33,156	45,021
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	658	773
Deferred tax benefit	136	172
Amounts included in accumulated AOCL, net of tax	522	601
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	(620)	(690)
Deferred tax benefit	(128)	(153)
Amounts included in accumulated AOCL, net of tax	$ (492)	$ (537)