Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Accounts receivable, allowance for doubtful accounts	$ 17	$ 21
Preferred stock, shares authorized	40,000,000	40,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares outstanding	11,659,467	762,590
Noncontrolling interest in consolidated partnership, redemption value	$ 914	$ 2,008
Series D Preferred Stock [Member]
Preferred stock, annual dividend rate		6.25%
Preferred stock, shares authorized		6,700,000
Preferred stock, par value		$ 0.01
Preferred stock, shares outstanding		6,245,156
Preferred stock, liquidation preference		$ 63,427
Series E Preferred Stock [Member]
Preferred stock, annual dividend rate	6.25%
Preferred stock, shares authorized	925,000
Preferred stock, par value	$ 0.01
Preferred stock, shares outstanding	925,000
Preferred stock, liquidation preference	$ 9,395