Investments in Unconsolidated Real Estate Joint Ventures Management, Leasing and Marketing Fees (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Management, Leasing and Marketing Fees [Line Items]
Management and Leasing Fees Paid by Unconsolidated Joint Ventures	$ 571	$ 716	$ 1,524	$ 1,689
Marketing Fees Paid by Unconsolidated Joint Venture	61	37	161	125
Total Management, Leasing and Marketing Fees Paid by Unconsolidated Joint Ventures	$ 632	$ 753	$ 1,685	$ 1,814