Revisions of Previously-Issued Financial Statements (Narratives) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 01, 2014	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Equity in earnings of equity method investments in real estate		$ 4,488	$ 10,042	$ 7,703	$ 7,178
Other income and (expenses)		4,204	170	810	852
Beginning equity balance, value	$ 2,485,724			2,385,397	2,485,724
Change in net unrealized loss on derivative instruments		(3,929)	(1,830)	18,807	(4,341)
Provision for income taxes		$ 1,973	2,671	2,764	3,309
Net cash provided by operating activities				113,693	101,123
Net cash used in investing activities				(250,320)	(94,853)
Revisions
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Equity in earnings of equity method investments in real estate			(932)		(547)
Other income and (expenses)			(776)		(1,046)
Beginning equity balance, value	426				426
Change in net unrealized loss on derivative instruments			(258)		(318)
Provision for income taxes			$ 7		(52)
Net cash provided by operating activities					(500)
Net cash used in investing activities					(500)
Distributions in Excess of Accumulated Earnings
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning equity balance, value	(431,095)			(567,806)	(431,095)
Adjustment to prior period balances	500
Distributions in Excess of Accumulated Earnings | Revisions
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning equity balance, value	8,593				8,593
Accumulated Other Comprehensive Loss
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning equity balance, value	(13,442)			(81,007)	(13,442)
Change in net unrealized loss on derivative instruments				$ 18,807	(4,650)
Adjustment to prior period balances	100
Accumulated Other Comprehensive Loss | Revisions
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning equity balance, value	(8,167)				(8,167)
Accumulated Other Comprehensive Loss | Revisions | Foreign currency translation
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning equity balance, value	$ (8,100)				$ (8,100)