CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Shares	Additional Paid In Capital	Cumulative Net Income	Cumulative Other Comprehensive Income (Loss)	Cumulative Common Distributions
Balance beginning (in shares) at Dec. 31, 2016		17,794,477
Balance beginning at Dec. 31, 2016	$ 935,004	$ 178	$ 1,474,067	$ 96,329	$ 26,957	$ (662,527)
Increase (Decrease) in Shareholders' Equity
Issuance of shares, net (in shares)		6,976,757
Issuance of shares, net	493,866	$ 70	493,796
Share grants (in shares)		18,836
Share grants	$ 1,361		1,361
Share repurchases (in shares)	(3,590)	(3,591)
Share repurchases	$ (264)		(264)
Equity in unrealized loss of investees	9,428				9,428
Unrealized gain on equity securities	24,042				24,042
Amounts reclassified from cumulative other comprehensive income to net income	(34)
Net income (loss) available for common shareholders	11,815			11,815
Distributions to common shareholders	(145,209)					(145,209)
Balance ending (in shares) at Dec. 31, 2017		24,786,479
Balance ending at Dec. 31, 2017	1,330,043	$ 248	1,968,960	108,144	60,427	(807,736)
Increase (Decrease) in Shareholders' Equity
Issuance of shares, net (in shares)		23,281,738
Issuance of shares, net	639,783	$ 233	639,550
Share grants (in shares)		19,925
Share grants	$ 1,523		1,523
Share repurchases (in shares)	(4,984)
Shares forfeitures or repurchases (in shares)		(5,239)
Share forfeitures or repurchases	$ (232)		(232)
Equity in unrealized loss of investees	(40)				(40)
Amounts reclassified from cumulative other comprehensive income to net income	(37)
Net income (loss) available for common shareholders	(22,255)			(22,255)
Distributions to common shareholders	(170,566)					(170,566)
Balance ending (in shares) at Dec. 31, 2018		48,082,903
Balance ending at Dec. 31, 2018	1,778,968	$ 481	2,609,801	146,882	106	(978,302)
Increase (Decrease) in Shareholders' Equity
Share grants (in shares)		136,100
Share grants	$ 3,098	$ 1	3,097
Share repurchases (in shares)	(15,588)
Shares forfeitures or repurchases (in shares)		(17,062)
Share forfeitures or repurchases	$ (473)		(473)
Amounts reclassified from cumulative other comprehensive income to net income	(196)				(196)
Equity in unrealized gain of investees	90				90
Unrealized loss on financial instrument	(200)				(200)
Net income (loss) available for common shareholders	30,335			30,335
Distributions to common shareholders	(105,868)					(105,868)
Balance ending (in shares) at Dec. 31, 2019		48,201,941
Balance ending at Dec. 31, 2019	$ 1,705,754	$ 482	$ 2,612,425	$ 177,217	$ (200)	$ (1,084,170)