Retirement Benefit Plans (Changes in Plan Assets and Funded Status of Pension Plans and Other Postretirement Benefit Plans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jul. 01, 2021
Change in plan assets:
Beginning balance	$ 266,268
Ending balance	271,846	$ 266,268
Funded status of the plan at year end				$ (500)
Pension Plan [Member]
Change in benefit obligation:
Beginning balance	266,414	241,404
Interest cost	4,663	6,511	$ 7,941
Actuarial (gain) loss	(11,131)	27,376
Benefits paid and administrative expenses	(9,683)	(8,877)
Ending balance	250,263	266,414	241,404
Change in plan assets:
Beginning balance	266,268	239,621
Actual return on plan assets	15,261	35,524
Employer contributions	0	0
Benefits paid and administrative expenses	(9,683)	(8,877)
Ending balance	271,846	266,268	239,621
Funded status of the plan at year end	21,583	(146)
SERP [Member]
Change in benefit obligation:
Beginning balance	2,046	1,935
Interest cost	30	46	65
Actuarial (gain) loss	(77)	194
Benefits paid and administrative expenses	(126)	(129)
Ending balance	1,873	2,046	1,935
Change in plan assets:
Beginning balance	0	0
Actual return on plan assets	0	0
Employer contributions	126	129
Benefits paid and administrative expenses	(126)	(129)
Ending balance	0	0	0
Funded status of the plan at year end	(1,873)	(2,046)
Other Benefits [Member]
Change in benefit obligation:
Beginning balance	1,998	2,399
Interest cost	19	46	85
Actuarial (gain) loss	32	(307)
Benefits paid and administrative expenses	(145)	(140)
Ending balance	1,904	1,998	2,399
Change in plan assets:
Beginning balance	0	0
Actual return on plan assets	0	0
Employer contributions	145	140
Benefits paid and administrative expenses	(145)	(140)
Ending balance	0	0	$ 0
Funded status of the plan at year end	$ (1,904)	$ (1,998)