Summary of Significant Accounting Policies (Additional Information 1) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 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			2,737	2,424
Amortization of deferred leasing costs totaled	4,800	3,700	13,500	10,800
Deferred income	22,540		22,540		21,993
Amortization of deferred revenue	2,700	2,400	7,700	6,500
Company recorded equity-based compensation expense net of repurchased awards and forfeits	3,700	2,600	10,500	7,900
Amount of the straight-line rent receivable on the balance sheets included in rents and other receivables, net	21,100		21,100		$ 17,300
Unsecured Revolving Credit Facility
Summary Of Significant Accounting Policies [Line Items]
Amortization of the deferred financing costs	$ 900	$ 800	$ 2,700	$ 2,400