Note 7 - Property, Equipment and Software - Property, Equipment and Software (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Property, equipment and software, gross	$ 201.1	$ 142.1
Accumulated depreciation	(156.9)	(90.3)
Property, equipment and software, net	44.2	51.8
Furniture, Fixtures, and Computer Equipment [Member]
Property, equipment and software, gross	$ 50.1	23.9
Furniture, Fixtures, and Computer Equipment [Member] | Maximum [Member]
Useful life (Year)	3 years
Furniture, Fixtures, and Computer Equipment [Member] | Minimum [Member]
Useful life (Year)	10 years
Leasehold Improvements [Member]
Property, equipment and software, gross	$ 47.7	27.6
Computer Equipment [Member]
Property, equipment and software, gross	$ 103.3	$ 90.6
Computer Equipment [Member] | Maximum [Member]
Useful life (Year)	3 years
Computer Equipment [Member] | Minimum [Member]
Useful life (Year)	7 years