Note 3 - Revenues - Disaggregated Revenues (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenues	$ 725.3	$ 677.6	$ 2,146.1	$ 2,004.2
UNITED STATES
Revenues	604.1	564.9	1,778.8	1,680.1
UNITED KINGDOM
Revenues	53.3	48.5	156.2	140.4
Other Countries [Member]
Revenues	67.9	64.2	211.1	183.7
Insurance [Member]
Revenues	725.3	677.6	2,146.1	2,004.2
Insurance [Member] \| Underwriting [Member]
Revenues	506.9	475.2	1,512.8	1,413.7
Insurance [Member] \| Claims [Member]
Revenues	$ 218.4	$ 202.4	$ 633.3	$ 590.5

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details