Retirement Benefit Plans (Schedule of Expected Benefit Payments) (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
2019	$ 2,475
2020	2,560
2022	2,669
2023	2,760
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	2,819
2024 - 2028	14,232
Total	27,515
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
2019	215
2020	234
2022	250
2023	238
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	232
2024 - 2028	902
Total	$ 2,071