Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Parent Company [Member]
Allowance for doubtful accounts receivable	$ 9,577	$ 6,725
Deferred costs accumulated amortization	85,971	83,529
Accumulated amortization of acquired lease intangible assets	69,324	56,695
Accumulated accretion of acquired lease intangible liabilities	$ 28,689	$ 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 6-7, units issued	3,000,000	13,000,000
Preferred units of Series 6-7, units outstanding	3,000,000	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	170,076,671	104,497,286
Exchangeable operating partnership units aggregate redemption value	$ 10,235	$ 10,630
Treasury stock, shares held at cost	349,660	347,903
Partnership Interest [Member]
Allowance for doubtful accounts receivable	$ 9,577	$ 6,725
Deferred costs accumulated amortization	85,971	83,529
Accumulated amortization of acquired lease intangible assets	69,324	56,695
Accumulated accretion of acquired lease intangible liabilities	$ 28,689	$ 23,538
Preferred units of general partner par value per unit	$ 0.01	$ 0.01
Preferred units of Series 6-7, units issued	3,000,000	13,000,000
Preferred units of Series 6-7, units outstanding	3,000,000	13,000,000
Preferred stock, liquidation preferences per share	$ 25	$ 25
General partner units, outstanding	170,076,671	104,497,286
Limited partner units, outstanding	154,170	154,170