Note 13 - Mortgages and Construction Loan Payable - Mortgages Payable (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Deferred financing costs, net		$ (1.5)
Balance, Net		$ 4,831.8	$ 4,381.5
Weighted Average [Member]
Interest Rate	[1]	3.46%	3.48%
Mortgages [Member]
Total		$ 410.6	$ 430.8
Interest Rate	[1]	4.97%
Fair value debt adjustments, net		$ 7.9	13.1
Deferred financing costs, net		(1.5)	(2.5)
Balance, Net		$ 484.0	$ 492.4
Mortgages [Member] | Minimum [Member]
Interest Rate		3.23%	3.23%
Mortgages [Member] | Maximum [Member]
Interest Rate		7.23%	9.75%
Mortgages [Member] | Weighted Average [Member]
Interest Rate	[1]		4.89%
Construction Loans [Member]
Total		$ 67.0	$ 51.0
Interest Rate		3.56%	4.23%
Balance, Net		$ 67.0

[1] Weighted-average interest rate