Note 18 - Supplemental Schedule of Non-cash Investing / Financing Activities - Non-cash Investing and Financing Activities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Acquisition of real estate interests through proceeds held in escrow	$ 0		$ 36,076		$ 0
Proceeds deposited in escrow through sale of real estate interests	0		5,106		41,949
Disposition of real estate interests through the issuance of mortgage receivable	0		3,750		14,700
Disposition of real estate interests by a deed in lieu/foreclosure of debt	0		3,892		7,444
Forgiveness of debt due to a deed in lieu/foreclosure	0		6,905		12,415
Capital expenditures accrual	37,411		65,900		60,611
Surrender of restricted common stock	5,395		4,030		4,360
Dividends payable	5,366		126,274		130,262
Adjustment to estimated redemption value (2)	(2,160)	[1]	0	[1]	7,521
Increase in real estate and other assets, net	0		7,884		0
Increase in mortgages payable, other liabilities and noncontrolling interests	0		7,747		0
Decrease in real estate and other assets	0		0		300,299
Increase in investments in and advances to real estate joint ventures	0		0		62,429
Decrease in mortgages and construction loan payable, other liabilities and noncontrolling interests	$ 0		$ 0		$ 248,274

[1] During the year ended December 31, 2020, the Company recorded an adjustment of $2.2 million to the estimated redemption fair market value of this noncontrolling interest in accordance with the provisions of the joint venture agreement and ASC 480 – Accounting for Redeemable Equity Instruments. The Company assesses the fair market value of this noncontrolling interest on a recurring basis and determined that its valuation was classified within Level 3 of the fair value hierarchy. The estimated fair market value of this noncontrolling interest was based upon a discounted cash flow model, for which a capitalization rate of 5.50% and discount rate of 6.50% were utilized in the model based upon unobservable rates that the Company believes to be within a reasonable range of current market rates. No adjustment to fair value was required during the year ended December 31, 2019.