Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Allowance for doubtful accounts receivable	$ 5,460	$ 5,295
Straight-line rent receivable allowance	3,561	1,365
Accumulated amortization of acquired lease intangible assets	$ (56,695)	$ (45,639)
General partner units, outstanding	104,497,286	97,213,000
Limited Partners' Capital Account, Units Outstanding	154,000	154,000
Parent Company [Member]
Common Stock, Shares, Issued	104,497,286	97,212,638
Deferred costs accumulated amortization	$ 83,529	$ 76,823
Accumulated amortization of acquired lease intangible assets	56,694	45,639
Accumulated accretion of acquired lease intangible liabilities	$ 23,538	$ 17,555
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	13,000,000	13,000,000
Preferred units of Series 3-5, units outstanding	13,000,000	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	150,000,000	150,000,000
Exchangeable operating partnership units aggregate redemption value	$ 10,630	$ 10,502
Treasury stock, shares held at cost	347,903	417,862
Partnership Interest [Member]
Deferred costs accumulated amortization	$ 83,529	$ 76,823
Accumulated amortization of acquired lease intangible assets	56,694	45,639
Accumulated accretion of acquired lease intangible liabilities	$ 23,538	$ 17,555
Preferred stock, par value per share	$ 0.01	$ 0.01
Preferred units of Series 3-5, units issued	13,000,000	13,000,000
Preferred units of Series 3-5, units outstanding	13,000,000	13,000,000
Preferred stock, liquidation preferences per share	$ 25	$ 25