Investments in Unconsolidated Real Estate Joint Ventures (Joint Venture Fees) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Management, Leasing and Marketing Fees [Line Items]
Fees received	$ 1,332	$ 1,727	$ 2,453	$ 3,010
Development and Leasing Fee [Member]
Management, Leasing and Marketing Fees [Line Items]
Fees received	353	727	545	1,307
Loan Guarantee Fee [Member]
Management, Leasing and Marketing Fees [Line Items]
Fees received	182	187	364	383
Management and Marketing Fee [Member]
Management, Leasing and Marketing Fees [Line Items]
Fees received	$ 797	$ 813	$ 1,544	$ 1,320