Note 12 - Retirement Benefit Plans - Actuarial Gains (Losses), Benefit Cost, Cash Flows (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| Interest cost | $ (8.7) | $ (6.7) | $ (16.5) | $ (13.5) |
| Amortization of prior service cost | (0.1) | (0.1) | (0.2) | (0.2) |
| Amortization of net gain | (0.6) | (0.3) | (1.1) | (0.6) |
| Expected return on plan assets | 8.7 | 6.5 | 16.4 | 13.4 |
| Net periodic benefit cost | $ (0.7) | $ (0.6) | $ (1.4) | $ (0.9) |
| X | ||||||||||
- Definition Amount of net periodic benefit cost (credit) for defined benefit plan before contribution to money purchase section. No definition available.
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| X | ||||||||||
- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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| X | ||||||||||
- Definition Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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| X | ||||||||||
- Definition Amount of cost recognized for passage of time related to defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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