Note 21 - Income Taxes - Taxable Income and Provisions for Income Taxes (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income/(loss) before income taxes – U.S.		$ 4,331	$ 1,487	$ (23,810)
(Provision)/benefit for income taxes, net:
Federal tax provision		(2,876)	(1,592)	(50,653)
Total tax provision – U.S.		1,600	(880)	78,583
Net income		498,463	439,671	386,138
Taxable REIT Subsidiaries [Member]
(Provision)/benefit for income taxes, net:
Current		(1,221)	(704)	2,199
Deferred		(1,198)	(632)	(45,097)
Federal tax provision		(2,419)	(1,336)	(42,898)
Current		(43)	(66)	1,057
Deferred		(414)	(190)	(8,812)
State tax provision		(457)	(256)	(7,755)
Total tax provision – U.S.		(2,876)	(1,592)	(50,653)
Net income		1,455	(105)	(74,463)
Income/(loss) before taxes – Non-U.S.		2,384	(11,483)	138,253
Current (1)	[1]	(1,634)	(2,425)	24,393
Deferred		358	(47)	3,537
Non-U.S. tax benefit/(provision)		$ 1,276	$ 2,472	$ (27,930)

[1] The year ended December 31, 2016 includes $24.9 million in expense related to the sale of interests in properties located in Canada.