Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Restricted Cash and Cash Equivalents	$ 3,582	$ 2,658
Deferred costs accumulated amortization	104,972	101,093
Accumulated amortization of acquired lease intangible assets	237,924	219,689
Accumulated accretion of acquired lease intangible liabilities	$ 106,286	$ 92,746
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	220,000,000	220,000,000
Common stock, shares issued	167,555,322	167,904,593
Treasury stock, shares held at cost	430,536	390,163
Exchangeable operating partnership units aggregate redemption value	$ 23,352	$ 20,532
Partnership Interest [Member]
Restricted Cash and Cash Equivalents	3,582	2,658
Deferred costs accumulated amortization	104,972	101,093
Accumulated amortization of acquired lease intangible assets	237,924	219,689
Accumulated accretion of acquired lease intangible liabilities	$ 106,286	$ 92,746
General partner units, outstanding	167,555,322	167,904,593
Limited partner units, outstanding	349,902	349,902