Investments in Unconsolidated Real Estate Joint Ventures (Joint Venture Fees) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Management, Leasing and other services [Line Items]
Fees received	$ 1,194	$ 1,356	$ 3,362	$ 3,943
Management and Marketing Fee [Member]
Management, Leasing and other services [Line Items]
Fees received	471	567	1,156	1,696
Leasing and other fees [Member]
Management, Leasing and other services [Line Items]
Fees received	15	32	50	71
Expense reimbursements from unconsolidated joint ventures [Member]
Management, Leasing and other services [Line Items]
Fees received	$ 708	$ 757	$ 2,156	$ 2,176