Note 13 - Supplemental Schedule of Non-cash Investing / Financing Activities (Details) - Non-Cash Investing and Financing Activities - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Note 13 - Supplemental Schedule of Non-cash Investing / Financing Activities (Details) - Non-Cash Investing and Financing Activities [Line Items]
Acquisition of real estate interests by assumption of mortgage debt	$ 20,800	$ 210,232
Acquisition of real estate interests by issuance of redeemable units/partnership interest		6,122
Acquisition of real estate interests through proceeds held in escrow	39,849	71,116
Proceeds held in escrow through sale of real estate interests	36,733	147,728
Disposition of real estate interests by assignment of debt	15,744
Declaration of dividends paid in succeeding period	111,480	104,858	$ 111,143
Consolidation of Joint Ventures:
Increase in real estate and other assets	977,807	509,839
Increase in mortgages payable and other liabilities	694,530	373,879
Restricted Stock [Member]
Note 13 - Supplemental Schedule of Non-cash Investing / Financing Activities (Details) - Non-Cash Investing and Financing Activities [Line Items]
Issuance of restricted common stock	488	13,835
Restricted Stock [Member] | Non-cash [Member]
Note 13 - Supplemental Schedule of Non-cash Investing / Financing Activities (Details) - Non-Cash Investing and Financing Activities [Line Items]
Surrender of restricted common stock	$ (5,604)	$ (3,981)