Retirement Benefit Plans (Schedule of assumptions used to determine net periodic benefit cost) (Details) - Retirement Plans	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	1.93%	2.82%	2.47%
Expected return on plan assets (percent)	4.69%	5.00%	4.73%
Expected rate of salary increases (percent)	2.95%	3.24%	3.26%
Future pension rate increases (percent)	2.74%	3.04%	2.97%