Summary of Significant Accounting Policies (Additional Information 1) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Summary Of Significant Accounting Policies [Line Items]
Impairment losses	$ 0	$ 0	$ 0	$ 0
Goodwill	173,843		173,843		$ 173,843
Amortization of the deferred financing costs			1,815	1,626
Amortization of deferred leasing costs totaled	4,500	3,600	8,700	7,100
Deferred income	23,433		23,433		21,993
Amortization of deferred revenue	2,400	2,300	5,100	4,200
Company recorded equity-based compensation expense net of repurchased awards and forfeits	3,700	3,200	6,800	5,300
Amount of the straight-line rent receivable on the balance sheets included in rents and other receivables, net	19,700		19,700		$ 17,300
Unsecured Revolving Credit Facility [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization of the deferred financing costs	$ 900	$ 800	$ 1,800	$ 1,600