Note 5 - Leases - Maturities of Lease Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
2024, operating leases	$ 18.3
2024, financing leases	15.6
2025, operating leases	35.0
2025, financing leases	19.8
2026, operating leases	33.5
2026, financing leases	9.4
2027, operating leases	33.2
2027, financing leases	7.9
2028, operating leases	32.0
2028, financing leases	4.2
2029 and thereafter, operating leases	104.0
2029 and thereafter, finance lease	0.0
Total lease payments, operating leases	256.0
Total lease payments, finance leases	56.9
Less: Amount representing interest, operating leases	(35.7)
Less: Amount representing interest, finance leases	(5.8)
Present value of total lease payments, operating leases	220.3
Present value of total lease payments, finance leases	$ 51.1	$ 34.5