Retirement Benefit Plans - Total Accumulated Benefit Obligations and Plans with Accumulated Benefit Obligations in Excess of Plan Assets (Detail) - USD ($) $ in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| United States [Member] | ||
| Pension Plans, Postretirement and Other Employee Benefits [Line Items] | ||
| Total accumulated benefit obligations | $ 368.5 | $ 356.2 |
| Plans with accumulated benefit obligations in excess of plan assets: | ||
| Accumulated benefit obligation | 1.2 | 1.2 |
| Foreign [Member] | ||
| Pension Plans, Postretirement and Other Employee Benefits [Line Items] | ||
| Total accumulated benefit obligations | 697.0 | 641.0 |
| Plans with accumulated benefit obligations in excess of plan assets: | ||
| Accumulated benefit obligation | 26.1 | 24.8 |
| Plan assets at fair market value | $ 9.3 | $ 8.0 |