Consolidated Statement Of Changes In Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Preferred Stock [Member]	Additional paid-in capital [Member]	Treasury shares [Member]	Accumulated other comprehensive income (loss) [Member]	Distributions in excess of net income [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2013	$ 1,688,014	$ 534	$ 139	$ 2,003,863	$ (62,177)	$ 17,193	$ (271,915)	$ 377
Balance (in shares) at Dec. 31, 2013		53,361,261	13,850,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of nonvested shares, net		280,193
Issuance of nonvested shares, net	(683)	(3)		(3,571)	(2,891)
Amortization of nonvested shares	(1,697)			(1,697)
Share option expense	363			363
Foreign currency translation adjustment	(8,488)					(8,488)
Change in unrealized gain/loss on derivatives	6,424					6,424
Net income	43,533						43,533
Issuances of common shares (in shares)		1,566,675
Issuances of common shares	79,621	15		79,606
Stock option exercises, net (in shares)	19,105	19,105
Stock option exercises, net	(21)	0		(768)	(789)
Dividends to common and preferred shareholders	(51,312)						(51,312)
Balance at Mar. 31, 2014	$ 1,760,514	$ 552	$ 139	$ 2,089,868	$ (65,857)	$ 15,129	$ (279,694)	$ 377
Balance (in shares) at Mar. 31, 2014		55,227,234	13,850,000