Note 19 - Preferred Stock, Common Stock and Convertible Unit Transactions - Dividends Declared (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Common Stock (in dollars per share)	$ 0.84000	$ 0.68000	$ 0.54000
Series L Preferred Stock [Member]
Preferred Shares (in dollars per share)	1.28125	1.28125	1.28125
Series M Preferred Stock [Member]
Preferred Shares (in dollars per share)	$ 1.31250	$ 1.31250	$ 1.31250