Segment Information (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 ReportableSegment	Mar. 31, 2011 ReportableSegment
Company's reportable segments
Total revenues	$ 195,371	$ 192,271
Operating expenses	(73,419)	(64,556)
Net operating income	121,952	127,715
Unallocated expenses	(141,606)	(92,329)
Equity in net income of joint ventures	8,248	1,974
Impairment of joint venture investments	(560)	(35)
(Loss) income from continuing operations	(11,966)	37,325
Total gross real estate assets	8,282,321	8,496,743
Segment Information (Textual) [Abstract]
Number of reportable segments	3	3
Quantitative threshold of revenues, profit or loss and assets for identifying reportable segments	10.00%	10.00%
Impairment charges	13,517	3,856
Other Investments [Member]
Company's reportable segments
Total revenues	1,131	1,306
Operating expenses	(500)	(422)
Net operating income	631	884
Total gross real estate assets	47,511	47,762
Shopping Centers [Member]
Company's reportable segments
Total revenues	194,240	190,965
Operating expenses	(72,919)	(64,134)
Net operating income	121,321	126,831
Equity in net income of joint ventures	(659)	(2,978)
Total gross real estate assets	8,234,810	8,448,981
Brazil Equity Investment [Member]
Company's reportable segments
Equity in net income of joint ventures	8,907	4,952
Other [Member]
Company's reportable segments
Unallocated expenses	$ (141,606)	$ (92,329)