Investments in Unconsolidated Real Estate Joint Ventures (Joint Venture Fees) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Management, Leasing and other services [Line Items]
Fees received	$ 1,356	$ 1,239	$ 3,943	$ 3,580
Management and Marketing Fee [Member]
Management, Leasing and other services [Line Items]
Fees received	567	571	1,696	1,704
Leasing and other fees [Member]
Management, Leasing and other services [Line Items]
Fees received	32	12	71	122
Expense reimbursements from unconsolidated joint ventures [Member]
Management, Leasing and other services [Line Items]
Fees received	$ 757	$ 656	$ 2,176	$ 1,754