Note 20 - Supplemental Schedule of Non-Cash Investing/Financing Activities (Detail) - Non-Cash Investing and Financing Activities (USD $) In Thousands, unless otherwise specified	1 Months Ended		12 Months Ended
	Jun. 30, 2006	Apr. 30, 2006	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2006
Acquisition of real estate interests by assumption of mortgage debt			$ 117,912	$ 670	$ 577,604
Disposition of real estate interest by assignment of mortgage debt				81,000
Issuance of common stock			4,940	5,070	3,415
Surrender of common stock			581	1	288
Disposition of real estate through the issuance of loan receivables			14,297	975	1,366
Investment in real estate joint venture by contribution of properties and assignment of debt				149,034
Declaration of dividends paid in succeeding period			92,159	89,037	76,707
Increase in real estate and other assets				174,327	47,368
Increase in mortgage payable	34,900	23,400		144,803	35,104	131,200
Non-cash [Member]
Surrender of common stock			$ (596)	$ (840)	$ (164)