Note 17 - Supplemental Schedule of Non-cash Investing / Financing Activities - Non-cash Investing and Financing Activities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Acquisition of real estate interests by assumption of mortgage debt	$ 0		$ 0		$ 45,299
Acquisition of real estate interests through proceeds held in escrow	36,076		0		162,396
Proceeds deposited in escrow through sale of real estate interests	5,106		41,949		162,396
Disposition of real estate interests through the issuance of mortgage receivable	3,750		14,700		0
Disposition of real estate interests by a deed in lieu/foreclosure of debt	3,892		7,444		0
Forgiveness of debt due to a deed in lieu/foreclosure	6,905		12,415		0
Capital expenditures accrual	65,900		60,611		74,123
Surrender of restricted common stock	4,030		4,360		5,699
Dividends payable	126,274		130,262		128,892
Change in noncontrolling interest due to liquidation of partnership	0		0		64,948
Adjustment to estimated redemption value	0	[1]	7,521	[1]	0
Deemed contribution from noncontrolling interest	0		0		10,000
Increase in real estate and other assets, net	7,884		0		325,981
Increase in mortgages payable, other liabilities and noncontrolling interests	7,747		0		258,626
Decrease in real estate and other assets	0		300,299		0
Increase in investments in and advances to real estate joint ventures	0		(62,429)		0
Decrease in mortgages and construction loan payable, other liabilities and noncontrolling interests	$ 0		$ 248,274		$ 0

[1] During the year ended December 31, 2018, the Company recorded an adjustment of $7.5 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 revalues 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 5.00% and discount rate of 6.00% 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.