Investments in Unconsolidated Real Estate Joint Ventures (Joint Venture Fees) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Management, Leasing and Marketing Fees [Line Items]
Fees paid by unconsolidated joint ventures	$ 758	$ 562	$ 1,324	$ 1,277
Development Fee [Member]
Management, Leasing and Marketing Fees [Line Items]
Fees paid by unconsolidated joint ventures	70	(81)	78	(12)
Loan Guarantee Fee [Member]
Management, Leasing and Marketing Fees [Line Items]
Fees paid by unconsolidated joint ventures	146	40	187	80
Management and Leasing Fee [Member]
Management, Leasing and Marketing Fees [Line Items]
Fees paid by unconsolidated joint ventures	438	504	846	1,001
Marketing Fee [Member]
Management, Leasing and Marketing Fees [Line Items]
Fees paid by unconsolidated joint ventures	$ 104	$ 99	$ 213	$ 208