Note 14 - Supplemental Schedule of Non-Cash Investing / Financing Activities (Details) - Non-Cash Investing and Financing Activities (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Note 14 - 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	$ 36,716	$ 116,735
Acquisition of real estate interests by issuance of redeemable units	77,593
Issuance of restricted common stock	9,213	18,066
Surrender of restricted common stock	(3,176)	(1,555)
Disposition of real estate interests by assignment of debt		13,655
Disposition of real estate through the issuance of an unsecured obligation	3,513	1,750
Declaration of dividends paid in succeeding period	98,326	98,883	96,518
Consolidation of Joint Ventures:
Increase in real estate and other assets	228,200
Increase in mortgages payable	206,489
Noncash [Member]
Note 14 - Supplemental Schedule of Non-Cash Investing / Financing Activities (Details) - Non-Cash Investing and Financing Activities [Line Items]
Acquisition of real estate interests by issuance of redeemable units	$ 3,985