Note 4 - Investments In and Advances to Real Estate Joint Ventures - The Company's Share of Net Income/(Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Prudential Investment Program [Member]
Income of joint ventures, net	[1]	$ 2,300	$ 2,600	$ 4,700	$ 5,300
KIR [Member]
Income of joint ventures, net		32,000	9,100	45,500	17,800
CPP [Member]
Income of joint ventures, net		2,600	2,000	5,700	4,100
Other Institutional Joint Ventures [Member]
Income of joint ventures, net		4,100	0	5,600	0
Other Joint Venture Programs [Member]
Income of joint ventures, net		3,100	2,600	6,200	6,900
Joint Ventures [Member]
Income of joint ventures, net		$ 44,130	$ 16,318	$ 67,700	$ 34,070

[1] During the six months ended June 30, 2022, the Prudential Investment Program recognized an impairment charge on a property of $15.1 million, of which the Company’s share was $2.3 million.