Retirement Benefit Plans (Actual Allocation Percentage and Target Allocation Percentage for the U.S. Pension Plan Assets) (Details) - Pension Plan	Dec. 31, 2018	Dec. 31, 2017
U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Actual allocation	42.40%	47.20%
Non-U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Actual allocation	19.40%	21.10%
Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Actual allocation	37.70%	31.40%
Money market
Defined Benefit Plan Disclosure [Line Items]
Actual allocation	0.50%	0.30%
Minimum | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	36.00%
Minimum | Non-U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	16.00%
Minimum | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	30.00%
Minimum | Money market
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	0.00%
Maximum | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	54.00%
Maximum | Non-U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	24.00%
Maximum | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	40.00%
Maximum | Money market
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description	10.00%