Note 24 - Supplemental Financial Information - Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from rental properties	$ 292,909	$ 279,286	$ 287,115	$ 293,091	$ 296,501	$ 283,387	$ 289,080	$ 275,506	$ 1,152,401	$ 1,144,474	$ 958,888
Net income/(loss) attributable to the Company	$ 78,273	$ (43,545)	$ 203,409	$ 140,713	$ 379,201	$ 77,572	$ 127,000	$ 310,342	$ 378,850	$ 894,115	$ 424,001
Basic (in dollars per share)	$ 0.16	$ (0.13)	$ 0.46	$ 0.31	$ 0.87	$ 0.15	$ 0.27	$ 0.72	$ 0.79	$ 2.01	$ 0.89
Diluted (in dollars per share)	$ 0.16	$ (0.13)	$ 0.46	$ 0.31	$ 0.87	$ 0.15	$ 0.27	$ 0.71	$ 0.79	$ 2	$ 0.89