Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Distributions in Excess of Earnings	Non-controlling Interests	Series A Preferred Stock Preferred Stock	Series L Preferred Stock Preferred Stock
Beginning balance (in shares) at Dec. 31, 2017		43,784,939					60,592	8,080,740
Beginning balance at Dec. 31, 2017	$ 626,705	$ 44	$ 792,631	$ 1,631	$ (399,250)	$ 890	$ 1,508	$ 229,251
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	38		38
Common dividends ($0.125 per share)	(5,473)				(5,473)
Issuance of Series A Preferred Warrants	17		17
Dividends to holders of Series A Preferred Stock ($0.34375 per share)	(493)				(493)
Reclassification of Series A Preferred Stock to permanent equity (in shares)							82,841
Reclassification of Series A Preferred Stock to permanent equity	1,885		(175)				$ 2,060
Redemption of Series A Preferred Stock	1		1
Other comprehensive income (loss)	1,183			1,183
Net income (loss)	622				618	4
Ending balance (in shares) at Mar. 31, 2018		43,784,939					143,433	8,080,740
Ending balance at Mar. 31, 2018	624,485	$ 44	792,512	2,814	(404,598)	894	$ 3,568	$ 229,251
Beginning balance (in shares) at Dec. 31, 2017		43,784,939					60,592	8,080,740
Beginning balance at Dec. 31, 2017	626,705	$ 44	792,631	1,631	(399,250)	890	$ 1,508	$ 229,251
Increase (Decrease) in Stockholders' Equity
Reclassification of Series A Preferred Stock to permanent equity	5,615
Net income (loss)	2,571
Ending balance (in shares) at Jun. 30, 2018		43,795,073					307,510	8,080,740
Ending balance at Jun. 30, 2018	624,440	$ 44	792,245	3,221	(408,797)	839	$ 7,637	$ 229,251
Beginning balance (in shares) at Mar. 31, 2018		43,784,939					143,433	8,080,740
Beginning balance at Mar. 31, 2018	624,485	$ 44	792,512	2,814	(404,598)	894	$ 3,568	$ 229,251
Increase (Decrease) in Stockholders' Equity
Distributions to noncontrolling interests	(67)					(67)
Stock-based compensation expense (in shares)		10,134
Stock-based compensation expense	48		48
Common dividends ($0.125 per share)	(5,474)				(5,474)
Issuance of Series A Preferred Warrants	23		23
Dividends to holders of Series A Preferred Stock ($0.34375 per share)	(662)				(662)
Reclassification of Series A Preferred Stock to permanent equity (in shares)							164,077
Reclassification of Series A Preferred Stock to permanent equity	3,730		(339)				$ 4,069
Redemption of Series A Preferred Stock	1		1
Other comprehensive income (loss)	407			407
Net income (loss)	1,949				1,937	12
Ending balance (in shares) at Jun. 30, 2018		43,795,073					307,510	8,080,740
Ending balance at Jun. 30, 2018	624,440	$ 44	792,245	3,221	(408,797)	839	$ 7,637	$ 229,251
Beginning balance (in shares) at Dec. 31, 2018		43,795,073					1,281,804	8,080,740
Beginning balance at Dec. 31, 2018	617,275	$ 44	790,354	1,806	(436,883)	837	$ 31,866	$ 229,251
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	38		38
Common dividends ($0.125 per share)	(5,474)				(5,474)
Issuance of Series A Preferred Warrants	9		9
Dividends to holders of Series A Preferred Stock ($0.34375 per share)	(1,010)				(1,010)
Reclassification of Series A Preferred Stock to permanent equity (in shares)							389,577
Reclassification of Series A Preferred Stock to permanent equity	8,890		(822)				$ 9,712
Redemption of Series A Preferred Stock (in shares)							(1,500)
Redemption of Series A Preferred Stock	(38)		(1)				$ (37)
Other comprehensive income (loss)	(1,806)			(1,806)
Net income (loss)	291,623				291,797	(174)
Ending balance (in shares) at Mar. 31, 2019		43,795,073					1,669,881	8,080,740
Ending balance at Mar. 31, 2019	909,507	$ 44	789,578	0	(151,570)	663	$ 41,541	$ 229,251
Beginning balance (in shares) at Dec. 31, 2018		43,795,073					1,281,804	8,080,740
Beginning balance at Dec. 31, 2018	617,275	$ 44	790,354	1,806	(436,883)	837	$ 31,866	$ 229,251
Increase (Decrease) in Stockholders' Equity
Reclassification of Series A Preferred Stock to permanent equity	19,715
Net income (loss)	344,190
Ending balance (in shares) at Jun. 30, 2019		43,805,741					2,142,676	8,080,740
Ending balance at Jun. 30, 2019	966,260	$ 44	788,655	0	(105,634)	617	$ 53,327	$ 229,251
Beginning balance (in shares) at Mar. 31, 2019		43,795,073					1,669,881	8,080,740
Beginning balance at Mar. 31, 2019	909,507	$ 44	789,578	0	(151,570)	663	$ 41,541	$ 229,251
Increase (Decrease) in Stockholders' Equity
Distributions to noncontrolling interests	(47)					(47)
Stock-based compensation expense (in shares)		10,668
Stock-based compensation expense	44		44
Common dividends ($0.125 per share)	(5,476)				(5,476)
Issuance of Series A Preferred Warrants	31		31
Dividends to holders of Series A Preferred Stock ($0.34375 per share)	(1,150)				(1,150)
Reclassification of Series A Preferred Stock to permanent equity (in shares)							474,462
Reclassification of Series A Preferred Stock to permanent equity	10,825		(1,002)				$ 11,827
Redemption of Series A Preferred Stock (in shares)							(1,667)
Redemption of Series A Preferred Stock	(41)		4		(4)		$ (41)
Net income (loss)	52,567				52,566	1
Ending balance (in shares) at Jun. 30, 2019		43,805,741					2,142,676	8,080,740
Ending balance at Jun. 30, 2019	$ 966,260	$ 44	$ 788,655	$ 0	$ (105,634)	$ 617	$ 53,327	$ 229,251