Consolidated Balance Sheets (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Shares of preferred stock authorized	100,000,000.0
Shares of preferred stock issued and outstanding	0
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Shares of common stock authorized	200,000,000.0	200,000,000
Shares of common stock issued and outstanding	120,800,315	111,011,816
Common Stock, Shares, Outstanding	120,800,315	111,011,816
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	0	2,573,432
Preferred Stock, Shares Outstanding	0	2,573,432
Preferred Stock, Liquidation Preference Per Share	$ 25	$ 25