Note 17 - Stockholders' Equity - Outstanding Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2024	Dec. 31, 2023
Preferred stock, shares authorized (in shares)		7,054,000	7,054,000
Preferred stock, liquidation preference		$ 576,606	$ 484,179
Preferred stock, par value (in dollars per share)		$ 1	$ 1
Series L Preferred Stock [Member]
Preferred stock, shares authorized (in shares)		10,350	10,350
Shares issued and outstanding (in shares)		8,902	8,902
Preferred stock, liquidation preference		$ 222,543	$ 222,543
Dividend rate		5.125%	5.125%
Annual dividend per depository share (in dollars per share)		$ 1.28125	$ 1.28125
Preferred stock, par value (in dollars per share)		$ 1	$ 1
Redemption date		Aug. 16, 2022	Aug. 16, 2022
Series M Preferred Stock [Member]
Preferred stock, shares authorized (in shares)		10,580	10,580
Shares issued and outstanding (in shares)		10,465	10,465
Preferred stock, liquidation preference		$ 261,636	$ 261,636
Dividend rate		5.25%	5.25%
Annual dividend per depository share (in dollars per share)		$ 1.3125	$ 1.3125
Preferred stock, par value (in dollars per share)		$ 1	$ 1
Redemption date		Dec. 20, 2022	Dec. 20, 2022
Class N Preferred Stock [Member]
Preferred stock, shares authorized (in shares)	[1]	1,849
Shares issued and outstanding (in shares)	[1]	1,849
Preferred stock, liquidation preference	[1]	$ 92,427
Dividend rate	[1]	7.25%
Annual dividend per depository share (in dollars per share)	[1]	$ 3.625
Preferred stock, par value (in dollars per share)	[1]	$ 1
Redeemable Preferred Stock [Member]
Shares issued and outstanding (in shares)		21,216	19,367
Preferred stock, liquidation preference		$ 576,606	$ 484,179

[1] In connection with the RPT Merger, the Company issued 1,849 shares of Class N Cumulative Convertible Perpetual Preferred Shares with a par value of $1.00 per share, represented by 1,848,539 depositary shares, which had a fair market value of $105.6 million. The Class N Preferred Stock depositary shares are convertible at any time by the holders to 2.3071 of the Company’s common shares or under certain circumstances by the Company’s election. As of March 31, 2024, the Class N Preferred Stock was potentially convertible into 4.3 million shares of common stock.