Note 7 - Investments In and Advances to Real Estate Joint Ventures - Joint Venture Investments Accounted for Under the Equity Method, Debt Details (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Mortgage and notes payable		$ 1,638.7	$ 1,541.0
Prudential Investment Program [Member]
Mortgage and notes payable		$ 426.9	$ 495.8
Weighted average interest rate		2.02%	2.05%
Weighted average remaining term (Month)	[1]	45 months 18 days	37 months 6 days
KIR [Member]
Mortgage and notes payable		$ 492.6	$ 536.9
Weighted average interest rate		2.55%	3.87%
Weighted average remaining term (Month)	[1]	27 months 27 days	25 months 9 days
CPP [Member]
Mortgage and notes payable		$ 84.2	$ 84.9
Weighted average interest rate		1.85%	3.25%
Weighted average remaining term (Month)	[1]	55 months	30 months
Other Institutional Joint Ventures [Member]
Mortgage and notes payable	[2]	$ 232.9	$ 0.0
Weighted average interest rate	[2]	1.65%	0.00%
Weighted average remaining term (Month)	[1],[2]	59 months 21 days
Other Joint Venture Programs [Member]
Mortgage and notes payable	[2]	$ 402.1	$ 423.4
Weighted average interest rate	[2]	3.58%	3.41%
Weighted average remaining term (Month)	[1],[2]	83 months	86 months 21 days

[1] Average remaining term includes extensions

[2] As of the date of the Merger, the Company acquired ownership in 9 unconsolidated joint ventures, which had an aggregate $191.5 million of secured debt (including a fair market value adjustment of $0.8 million).