Investment in Partially Owned Entities (Details 1) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Schedule of net equity investment and share of net income or loss
Investment	$ 299,369	$ 316,711
Net Lease Strategic Asset Fund LP [Member]
Schedule of net equity investment and share of net income or loss
Description	Diversified portfolio of net lease assets
Ownership %	85.00%
Investment	16,914	26,508
Cobalt Industrial REIT II [Member]
Schedule of net equity investment and share of net income or loss
Description	Industrial portfolio
Ownership %	36.00%
Investment	112,696	113,623
D.R. Stephens Institutional Fund, LLC [Member]
Schedule of net equity investment and share of net income or loss
Description	Industrial and R&D assets
Ownership %	90.00%
Investment	35,970	36,218
Brixmor/IA JV, LLC [Member]
Schedule of net equity investment and share of net income or loss
Description	Retail Shopping Centers
Investment	96,674	103,567
Other Unconsolidated Entities [Member]
Schedule of net equity investment and share of net income or loss
Description	Various real estate investments
Investment	$ 37,115	$ 36,795