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Note 6 - Fair Value Measurements - Change in Level 3 Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Beginning of period fair value	$ 25.3	$ 4.0	$ 4.5	$ 1.1
Fair value adjustments	2.5	(2.0)	3.0	0.2
Transfers	0.0	0.0	0.0	0.7
Transfers from practical expedient	0.0	0.0	9.4	0.0
Purchases (sales) of securities, net	3.6	11.8	14.5	11.8
End of period fair value	$ 31.4	$ 13.8	$ 31.4	$ 13.8

X

- Definition

Amount of transfer of financial instrument classified as an asset into (out of) a practical expedient.

+ References

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- Definition

Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

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Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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