Retirement Benefit Plans - Accumulated Benefit Obligations (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Pension Plan
Defined Benefit Plan, Plan Assets, Category [Line Items]
Accumulated benefit obligation	$ 11.9	$ 10.9
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation	4.8	4.9
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation	4.6	4.6
Supplemental Employee Retirement Plan
Defined Benefit Plan, Plan Assets, Category [Line Items]
Accumulated benefit obligation	$ 7.2	$ 6.3