Note 5 - 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, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Kim Pru and Kim Pru II [Member]
Income of joint ventures, net		$ 2,800	$ 2,700	$ 5,700	$ 5,600
KIR [Member]
Income of joint ventures, net		17,200	9,900	31,800	18,900
CPP [Member]
Income of joint ventures, net		1,600	1,300	3,000	2,500
Other Joint Venture Programs [Member]
Income of joint ventures, net	[1]	900	5,100	800	9,000
Joint Ventures [Member]
Income of joint ventures, net		$ 22,533	$ 19,040	$ 41,287	$ 35,953

[1] During the three months ended June 30, 2018, a joint venture investment distributed cash proceeds resulting from the refinancing of an existing loan of which the Company’s share was $3.6 million. The distribution was in excess of the Company’s carrying basis in this joint venture investment and as such was recognized as income.