Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accumulated amortization of acquired lease intangible assets	$ 219,689	$ 148,280
General Partners' Capital Account, Units Outstanding	167,904,593	171,365,000
Limited Partners' Capital Account, Units Outstanding	350,000	350,000
Parent Company [Member]
Deferred costs accumulated amortization	$ 101,093	$ 93,291
Accumulated amortization of acquired lease intangible assets	219,689	148,280
Accumulated accretion of acquired lease intangible liabilities	$ 92,746	$ 56,550
Preferred stock, par value per share	$ 0.01	$ 0.01
Preferred stock, shares authorized	30,000,000	30,000,000
Preferred units of Series 3-5, units issued	0	0
Preferred units of Series 3-5, units outstanding	0	0
Preferred stock, liquidation preferences per share	$ 25	$ 25
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	220,000,000	220,000,000
Common Stock, Shares, Issued	167,904,593	171,364,908
Treasury stock, shares held at cost	390,163	366,628
Exchangeable operating partnership units aggregate redemption value	$ 20,532	$ 24,406
Partnership Interest [Member]
Deferred costs accumulated amortization	101,093	93,291
Accumulated amortization of acquired lease intangible assets	219,689	148,280
Accumulated accretion of acquired lease intangible liabilities	$ 92,746	$ 56,550
Preferred stock, par value per share	$ 0.01	$ 0.01
Preferred units of Series 3-5, units issued	0	0
Preferred units of Series 3-5, units outstanding	0	0
Preferred stock, liquidation preferences per share	$ 25	$ 25
General Partners' Capital Account, Units Outstanding	167,904,000