Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	9 Months Ended		12 Months Ended
	Sep. 30, 2020		Dec. 31, 2019
Common stock, par value per share	$ 0.01		$ 0.01
Common stock, shares authorized	145,000,000		145,000,000
Common stock, shares issued	114,369,812		114,246,393
Common stock, shares outstanding	114,369,812		114,246,393
Preferred Stock, Par or Stated Value Per Share	$ 0.01		$ 0.01
Preferred Stock, Shares Authorized	20,000,000		20,000,000
Preferred Stock, Dividend Rate, Percentage	8.50%		8.50%
Preferred Stock, Shares Issued	867,846		867,846
Preferred Stock, Shares Outstanding	867,846		867,846
Preferred Stock, Liquidation Preference Per Share	$ 50.00	[1]	$ 50.00
Redeemable stock, shares issued and outstanding	119,374		107,162
General Partners' Capital Account, Units Outstanding	114,369,812
Limited Partners' Capital Account, Units Outstanding	4,058,258
Limited Partner [Member]
Redeemable stock, shares issued and outstanding	119,374		107,162
General Partners' Capital Account, Units Outstanding	114,369,812		114,246,393
Limited Partners' Capital Account, Units Outstanding	4,058,258		4,067,174
Preferred Units, Issued	867,846		867,846
Preferred Units, Outstanding	867,846		867,846

[1] The total liquidation preference for the outstanding preferred stock is $43.4 million.