Note 16 - Retirement Benefit Plans - Actuarial Gains and Losses (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Amortization of actuarial loss	$ 1.3	$ 0.5	$ 0.0
Pension Plan [Member]
Accumulated unamortized actuarial loss	(84.7)	(70.4)
Actuarial loss	(17.5)	(18.8)
Tax at source on current year actuarial gain	3.2	3.5
Prior service cost	0.4	0.5
Amortization of actuarial loss	1.3	0.5
Accumulated unamortized actuarial loss	$ (97.3)	$ (84.7)	$ (70.4)

Amount of accumulated unamortized actuarial gain (loss) of defined benefit plan.

No definition available.

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- Definition

Amount of accumulated unamortized actuarial gain (loss) recognized during the year before tax of defined benefit plan.

+ References

No definition available.

+ Details

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- Definition

Amount of tax on accumulated unamortized actuarial gain (loss) of defined benefit plan during the year.

+ References

No definition available.

+ Details

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- Definition

Amount, before tax, of accumulated other comprehensive (income) loss for cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (j)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

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- Definition

Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480482/715-20-55-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
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-Name Accounting Standards Codification
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-Paragraph 3A
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-Publisher FASB
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
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-Name Accounting Standards Codification
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-Publisher FASB
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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