Reportable Segments Reportable Segments (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Segment Reporting Information [Line Items]
Net operating property income, including discontinued operations	$ 22,988	$ 22,036
Plus rental property operating expenses	14,419	12,886
Fee income	3,889	3,713
Reimbursed Expenses	1,376	1,512
Residential lot and multi-family unit sales, net of cost of sales, including gain on sale of undepreciated investment properties	385	2,253
Plus residential lot, multi-family unit and outparcel cost of sales	564	2,569
Net operating income from discontinued operations not included in revenues	(224)	(2,243)
Other income	1,465	513
Total consolidated revenues	47,164	45,487
Third Party and Joint Venture [Member]
Segment Reporting Information [Line Items]
Third party management and leasing expense reimbursements	$ 2,302	$ 2,248