Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
Common stock, shares outstanding	113,916,208
General Partners' Capital Account, Units Outstanding	113,916,208
Limited Partners' Capital Account, Units Outstanding	4,105,171
Preferred Stock, Liquidation Preference Per Share	$ 50.00
Limited Partner [Member]
General Partners' Capital Account, Units Outstanding	113,844,267	113,844,267
Limited Partners' Capital Account, Units Outstanding	4,111,301	4,111,301
Preferred Units, Issued	867,846	867,846
Preferred Units, Outstanding	867,846	867,846
Parent Company [Member]
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	145,000,000	145,000,000
Common stock, shares issued	113,916,208	113,844,267
Common stock, shares outstanding	113,916,208	113,844,267
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	20,000,000	20,000,000
Preferred Stock, Shares Issued	867,846	867,846
Preferred Stock, Shares Outstanding	867,846	867,846
Preferred Stock, Liquidation Preference Per Share	$ 50	$ 50