Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accumulated amortization of acquired lease intangible assets	$ (148,280)	$ (56,695)
General Partners' Capital Account, Units Outstanding	171,364,908	104,497,000
Limited Partners' Capital Account, Units Outstanding	350,000	154,000
Parent Company [Member]
Deferred costs accumulated amortization	$ 93,291	$ 83,529
Accumulated amortization of acquired lease intangible assets	148,280	56,695
Accumulated accretion of acquired lease intangible liabilities	$ 56,550	$ 23,538
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	13,000,000
Preferred units of Series 3-5, units outstanding	0	13,000,000
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	150,000,000
Common Stock, Shares, Issued	171,364,908	104,497,286
Treasury stock, shares held at cost	366,628	347,903
Exchangeable operating partnership units aggregate redemption value	$ 24,206	$ 10,630
Partnership Interest [Member]
Deferred costs accumulated amortization	93,291	83,529
Accumulated amortization of acquired lease intangible assets	148,546	56,694
Accumulated accretion of acquired lease intangible liabilities	$ 57,170	$ 23,538
Preferred stock, par value per share	$ 0.01	$ 0.01
Preferred units of Series 3-5, units issued	0	13,000,000
Preferred units of Series 3-5, units outstanding	0	13,000,000
Preferred stock, liquidation preferences per share	$ 25	$ 25