Retirement Benefit Plans (Fair Values of Pension Plan Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Total Assets including Common Trust Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 700,535	$ 859,883
Level 1 [Member] | Total Assets including Common Trust Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	200,500	455,917
Level 2 [Member] | Total Assets including Common Trust Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	31,268	40,254
Pension Benefits [Member] | Cash And Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,050	21,280
Pension Benefits [Member] | Total Cash and Cash-Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,050	21,280
Pension Benefits [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	60,845	69,941
Pension Benefits [Member] | Mutual Fund-Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	344	20,428
Pension Benefits [Member] | Exchange Traded Fund (ETF)-Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,087	4,049
Pension Benefits [Member] | Total Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	66,276	94,418
Pension Benefits [Member] | Domestic And Foreign Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	50,956	109,610
Pension Benefits [Member] | Mutual Funds-Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	105,486	270,863
Pension Benefits [Member] | Total Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	156,442	380,473
Pension Benefits [Member] | Total Real Assets At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	231,768	496,171
Pension Benefits [Member] | Common Trust Fund (Fixed Income) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	410,280	294,112
Pension Benefits [Member] | Common Trust Fund (Real Assets) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	58,487	69,600
Pension Benefits [Member] | Level 1 [Member] | Cash And Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,050	21,280
Pension Benefits [Member] | Level 1 [Member] | Total Cash and Cash-Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,050	21,280
Pension Benefits [Member] | Level 1 [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	29,577	29,687
Pension Benefits [Member] | Level 1 [Member] | Mutual Fund-Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	344	20,428
Pension Benefits [Member] | Level 1 [Member] | Exchange Traded Fund (ETF)-Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,087	4,049
Pension Benefits [Member] | Level 1 [Member] | Total Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	35,008	54,164
Pension Benefits [Member] | Level 1 [Member] | Domestic And Foreign Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	50,956	109,610
Pension Benefits [Member] | Level 1 [Member] | Mutual Funds-Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	105,486	270,863
Pension Benefits [Member] | Level 1 [Member] | Total Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	156,442	380,473
Pension Benefits [Member] | Level 1 [Member] | Total Real Assets At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	200,500	455,917
Pension Benefits [Member] | Level 2 [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	31,268	40,254
Pension Benefits [Member] | Level 2 [Member] | Total Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	31,268	40,254
Pension Benefits [Member] | Level 2 [Member] | Total Real Assets At Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 31,268	$ 40,254