Investments in Unconsolidated Real Estate Joint Ventures (Joint Venture Fees) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Management, Leasing and Marketing Fees [Line Items]
Fees received	$ 806	$ 1,253	$ 3,259	$ 4,263
Development and Leasing Fee [Member]
Management, Leasing and Marketing Fees [Line Items]
Fees received	65	325	611	1,632
Loan Guarantee Fee [Member]
Management, Leasing and Marketing Fees [Line Items]
Fees received	85	182	449	564
Management and Marketing Fee [Member]
Management, Leasing and Marketing Fees [Line Items]
Fees received	$ 656	$ 746	$ 2,199	$ 2,067