Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Restricted Cash and Cash Equivalent	$ 2,377	$ 2,542
Deferred costs accumulated amortization	113,959	108,381
Accumulated amortization of acquired lease intangible assets	284,880	259,310
Accumulated accretion of acquired lease intangible liabilities	$ 145,966	$ 131,676
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	220,000,000	220,000,000
Common stock, shares issued	169,680,138	167,571,218
Treasury stock, shares held at cost	459,828	440,574
Exchangeable operating partnership units aggregate redemption value	$ 34,878	$ 47,092
General partner units, outstanding	169,680,000	167,571,000
Limited partner units, outstanding	765,000	746,000
Partnership Interest [Member]
Restricted Cash and Cash Equivalent	$ 2,377	$ 2,542
Deferred costs accumulated amortization	113,959	108,381
Accumulated amortization of acquired lease intangible assets	284,880	259,310
Accumulated accretion of acquired lease intangible liabilities	$ 145,966	$ 131,676
General partner units, outstanding	169,680,138	167,571,218
Limited partner units, outstanding	765,046	746,433