Consolidated Balance Sheets (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Shares of preferred stock authorized	100,000,000
Shares of preferred stock issued and outstanding	2,573,432
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Shares of common stock authorized	200,000,000	200,000,000
Shares of common stock issued and outstanding	111,011,816.000	99,783,686
Common Stock, Shares, Outstanding	111,011,816	99,783,686
Series D Convertible Preferred Stock
Preferred Stock, dividend rate (as a percent)	7.00%	7.00%
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Shares of preferred stock authorized	10,000,000	10,000,000
Shares of preferred stock issued and outstanding	2,573,432	2,975,432
Preferred Stock, Shares Outstanding	2,573,432	2,975,432
Preferred Stock, Liquidation Preference Per Share	$ 25	$ 25