Investments in Unconsolidated Real Estate Joint Ventures (Joint Venture Fees) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Management, Leasing and other services [Line Items]
Fees received	$ 1,443	$ 1,342
Management and Marketing Fee [Member]
Management, Leasing and other services [Line Items]
Fees received	541	566
Leasing and other fees [Member]
Management, Leasing and other services [Line Items]
Fees received	20	31
Expense reimbursements from unconsolidated joint ventures [Member]
Management, Leasing and other services [Line Items]
Fees received	$ 882	$ 745