Note 8 - Fair Value Disclosures - Fair Value Measurements of Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent) (Details) - USD ($) $ in Thousands		Mar. 31, 2024		Dec. 31, 2023
Alternative investment		$ 8,473		$ 7,890
CREO JV [Member]
Alternative investment	[1]	5,362		4,783
Unfunded commitments	[1]	9,978		10,398
U.S. Insurance JV [Member]
Alternative investment		$ 3,111	[2]	$ 3,107	[3]

[1] The CREO JV invests in primarily multi-family commercial real estate mortgage-backed loans and below-investment grade rated tranches in CRE CLOs collateralized by mostly commercial real estate mortgage-backed loans.

[2] The U.S. Insurance JV invests in USD denominated debt issued by small and medium size insurance and reinsurance companies.

[3] The U.S. Insurance JV invests in USD denominated debt issued by small and medium size insurance and reinsurance companies.