Acquired Intangible Assets and Liabilities (Schedule of Future Amortization Finite Lived Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Acquired in-place lease value
Finite-Lived Intangible Assets [Line Items]
2019	$ 158,095
2020	123,450
2021	98,916
2022	77,056
2023	65,518
Thereafter	251,333
Net	774,368	$ 859,567
Tenant relationship value and trade names
Finite-Lived Intangible Assets [Line Items]
2019	143,818
2020	143,818
2021	143,818
2022	143,818
2023	143,818
Thereafter	1,328,698
Net	$ 2,047,788