Real Estate Intangibles (Details 1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Real Estate Intangible Amortization [Abstract]
Rental income related to above/below market tenant leases, net	$ (333)	$ 267	$ (684)	$ 571
Property operating expenses related to above/below market ground leases, net	(312)	(307)	(679)	(619)
Depreciation and amortization related to in place lease intangibles and lease commissions	$ (33,763)	$ (35,439)	$ (66,024)	$ (74,741)