Consolidated Statement of Changes in Equity (USD $) In Thousands, except Share data	Common Stock	Preferred Stock	Additional paid-in capital	Treasury shares	Accumulated other comprehensive income	Distributions in excess of net income	Noncontrolling Interests	Total
Balance at Dec. 31, 2010	$ 477	$ 167	$ 1,785,371	$ (39,762)	$ 38,842	$ (181,856)	$ 28,019	$ 1,631,258
Balance (in shares) at Dec. 31, 2010	47,769,422	16,650,000
Restricted share units issued to Trustees (in shares)	10,519
Restricted share units issued to Trustees			502					502
Issuance of nonvested shares, including nonvested shares issued for the payment of bonuses (in shares)	137,020
Issuance of nonvested shares, including nonvested shares issued for the payment of bonuses	1		1,967					1,968
Amortization of nonvested shares			2,119					2,119
Share option expense			377					377
Foreign currency translation adjustment					9,558			9,558
Foreign currency translation gain reclassified from accumulated other comprehensive income into earnings from the substantial liquidation of foreign net assets					(23,236)			(23,236)
Change in unrealized gain/loss on derivatives					(3,846)			(3,846)
Loss reclassified from accumulated other comprehensive income into earnings from termination of interest rate swaps					4,586			4,586
Net income						41,733	2	41,735
Purchase of 66,368 common shares for treasury				(3,070)				(3,070)
Issuances of common shares (in shares)	4,379
Issuances of common shares			304					304
Stock option exercises, net (in shares)	71,229							71,229
Stock option exercises, net	1		1,503	(2,002)				(498)
Dividends to common and preferred shareholders						(80,412)		(80,412)
Balance at Jun. 30, 2011	$ 479	$ 167	$ 1,792,143	$ (44,834)	$ 25,904	$ (220,535)	$ 28,021	$ 1,581,345
Balance (in shares) at Jun. 30, 2011	47,992,569	16,650,000