Note 9 - Other Real Estate Investments - Preferred Equity Investments - Income Statement Disclosures (Details) - USD ($) $ 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
Operating expenses									(869,969)	(823,197)	(683,582)
Interest expense									(192,549)	(218,891)	(203,759)
Depreciation and amortization									(355,320)	(344,527)	(258,074)
Other expense, net									2,313	2,234	(8,544)
Income from continuing operations									300,823	343,572	310,315
Discontinued Operations:
										6	37,612
Net (loss)/income from U.S. taxable REIT subsidiaries									386,138	900,143	435,880
Preferred Equity Investments [Member]
Revenues from rental properties									102,600	122,100	146,000
Operating expenses									(27,400)	(35,600)	(47,000)
Interest expense									(26,700)	(35,700)	(47,100)
Depreciation and amortization									(6,700)	(11,400)	(19,200)
Other expense, net									(11,500)	(9,200)	(7,200)
Income from continuing operations									30,300	30,200	25,500
Discontinued Operations:
Gain on disposition of properties											31,500
											31,500
Gain on sale of operating properties									5,300	6,000
Net (loss)/income from U.S. taxable REIT subsidiaries									$ 35,600	$ 36,200	$ 57,000