Retirement Benefit Plans (Assumptions Used in Accounting for Postretirement Benefit Plans) (Details) - Other Postretirement Benefits Plan	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average discount rates for pension benefit obligation	2.12%	1.37%
Weighted average discount rates for net periodic benefit cost	1.37%
Health care cost trend rate assumed for next year	6.50%	6.25%
Rate to which the cost trend rate is assumed to decline (ultimate trend rate)	4.50%	5.00%
Year that the rate reaches the ultimate trend rate	2029	2027
Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average discount rates for net periodic benefit cost		1.37%
Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average discount rates for net periodic benefit cost		2.65%