Note 8 - Goodwill and Intangible Assets - Intangible Assets and Related Accumulated Amortization (Details) - USD ($) $ in Millions	Sep. 30, 2024	Mar. 31, 2024	Dec. 31, 2023
Cost		$ 988.4	$ 975.2
Accumulated amortization		(565.8)	(503.5)
Net	$ 422.6	$ 422.6	$ 471.7
Technology-Based Intangible Assets [Member]
Weighted average useful life (Year)	8 years		8 years
Cost	$ 375.0		$ 370.2
Accumulated amortization	(286.2)		(261.2)
Net	$ 88.8		$ 109.0
Marketing-Related Intangible Assets [Member]
Weighted average useful life (Year)	6 years		6 years
Cost	$ 43.6		$ 42.7
Accumulated amortization	(40.8)		(38.7)
Net	$ 2.8		$ 4.0
Contract-Based Intangible Assets [Member]
Weighted average useful life (Year)	6 years		6 years
Cost	$ 5.0		$ 5.0
Accumulated amortization	(5.0)		(5.0)
Net	$ 0.0		$ 0.0
Customer-Related Intangible Assets [Member]
Weighted average useful life (Year)	13 years		13 years
Cost	$ 549.4		$ 542.1
Accumulated amortization	(224.3)		(190.7)
Net	$ 325.1		$ 351.4
Database [Member]
Weighted average useful life (Year)	8 years		8 years
Cost	$ 15.4		$ 15.2
Accumulated amortization	(9.5)		(7.9)
Net	$ 5.9		$ 7.3

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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