Retirement Benefit Plans (Net Periodic Pension Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
U.S. Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 727	$ 681	$ 811
Expected return on plan assets	(1,987)	(2,047)	(2,074)
Amortization of actuarial loss	561	623	501
Net periodic pension (income) loss	(699)	(743)	(762)
Non-U.S. Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	144	142	153
Expected return on plan assets	(263)	(286)	(264)
Amortization of actuarial loss	72	200	10
Net periodic pension (income) loss	$ (47)	$ 56	$ (101)