Note 13 - Supplemental Schedule of Non-cash Investing / Financing Activities - Non-cash Investing and Financing Activities (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Proceeds deposited in escrow through sale of real estate interests	$ 150,697	$ 66,431
Acquisition of real estate interests through proceeds held in escrow	115,853	66,044
Acquisition of real estate interests by assumption of mortgage debt		33,174
Issuance of common stock		85
Surrender of restricted common stock	(5,599)	(6,904)
Declaration of dividends paid in succeeding period	123,270	118,136	$ 124,517
Capital expenditures accrual	56,879	17,604
Deemed contribution from noncontrolling interest	10,000
Increase in real estate and other assets	325,981	316,772
Increase in mortgages payable, other liabilities and non-controlling interests	$ 258,626	$ 194,964