Acquired Intangible Assets and Liabilities (Schedule of Estimated Annual Amortization of Below Market Leases) (Details) - Below-Market Leases, Net of Above-Market Leases $ in Thousands	Mar. 31, 2019 USD ($)
Finite-Lived Intangible Assets [Line Items]
Remainder of 2019	$ (9,150)
2020	(3,912)
2021	889
2022	7,923
2023	12,070
Thereafter	78,803
Total	$ 86,623