Note 12 - Notes Payable - Maturities of All Unsecured Notes Payable (Details) - Unsecured Debt [Member] $ in Millions	Dec. 31, 2023 USD ($)
2024	$ 646.2
2025	740.5
2026	773.0
2027	433.7
2028	409.6
Thereafter	4,300.0
Total	$ 7,303.0

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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