CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares						3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 12, 2019	May 20, 2019	Mar. 06, 2019	Feb. 15, 2019	Apr. 15, 2013	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Preferred Stock, dividend rate										7.50%		7.50%
Common stock, cash dividends declared (in dollars per share)	$ 0.20		$ 0.20			$ 0.20	$ 0.20	$ 0.20	$ 0.20
Preferred Stock 7.50% Series B Cumulative Redeemable - Liquidation Preference $25.00 per Share
Dividend declared per share, preferred stock (in dollars per share)		$ 0.46875		$ 0.46875		0.46875	$ 0.46875	$ 0.46875	$ 0.46875
Preferred Stock | Preferred Stock 7.50% Series B Cumulative Redeemable - Liquidation Preference $25.00 per Share
Preferred Stock, dividend rate					7.50%					7.50%	7.50%
Preferred Stock, liquidation preference per share (in dollars per share)					$ 25.00	$ 25.00				$ 25.00		$ 25