Note 4 - Investment In and Advances to Real Estate Joint Ventures - The Company's Share of Net Income/(Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Prudential Investment Program [Member]
Income of joint ventures, net	$ 9,800	$ 2,400
KIR [Member]
Income of joint ventures, net	9,300	13,400
CPP [Member]
Income of joint ventures, net	2,700	3,100
Other Institutional Joint Ventures [Member]
Income of joint ventures, net	700	1,500
Other Joint Venture Programs [Member]
Income of joint ventures, net	1,700	3,200
Joint Ventures [Member]
Income of joint ventures, net	$ 24,204	$ 23,570