Summary of Significant Accounting Policies (Additional Information 1) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Summary of Significant Accounting Policies [Abstract]
Amortization of the deferred financing costs	$ 962	$ 872
Amortization of deferred leasing costs totaled	4,900	4,200
Deferred income	28,679		$ 25,305
Amortization of deferred revenue	2,900	2,600
Company recorded equity-based compensation expense net of repurchased awards and forfeits	3,500	$ 3,100
Equity based compensation associated with the acceleration of equity awards	$ 1,400
Revenue, Practical Expedient, Remaining Performance Obligation [true/false]	true
Amount of the straight-line rent receivable on the balance sheets included in rents and other receivables, net	$ 26,100		$ 23,400