Deferred Financing and Leasing Costs (Intangible Amortization Schedule) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Deferred financing and leasing costs, net	$ 159,250	$ 147,038
Leases, Acquired-in-Place, Market Adjustment [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2018	242
2019	(265)
2020	(858)
2021	(891)
2022	(762)
Thereafter	(2,637)
Deferred financing and leasing costs, net	(5,171)
Leases, Acquired-in-Place [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2018	9,748
2019	6,437
2020	3,664
2021	2,839
2022	2,158
Thereafter	5,551
Deferred financing and leasing costs, net	$ 30,397