Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Shares	Common Shares	Additional Paid-in Capital	Accumulated Distributions in Excess of Net Income	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Beginning balance at Dec. 31, 2019	$ 848,255	$ 92,427	$ 798	$ 1,169,557	$ (436,361)	$ 1,819	$ 20,015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares, net of issuance costs	(385)			(385)
Share-based compensation, net of shares withheld for employee taxes	3,829		3	3,826
Dividends declared to common shareholders	(17,593)				(17,593)
Dividends declared to preferred shareholders	(5,026)				(5,026)
Distributions declared to noncontrolling interests	(420)						(420)
Dividends declared to deferred shares	(136)				(136)
Other comprehensive income - gain (loss) adjustment	(18,500)					(18,071)	(429)
Net income (loss)	(4,607)				(4,501)		(106)
Ending balance at Sep. 30, 2020	805,417	92,427	801	1,172,998	(463,617)	(16,252)	19,060
Beginning balance at Jun. 30, 2020	806,438	92,427	800	1,171,287	(459,994)	(17,167)	19,085
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation, net of shares withheld for employee taxes	1,712		1	1,711
Dividends declared to preferred shareholders	(1,676)				(1,676)
Other comprehensive income - gain (loss) adjustment	936					915	21
Net income (loss)	(1,993)				(1,947)		(46)
Ending balance at Sep. 30, 2020	805,417	92,427	801	1,172,998	(463,617)	(16,252)	19,060
Beginning balance at Dec. 31, 2020	801,369	92,427	801	1,174,315	(471,017)	(14,132)	18,975
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares, net of issuance costs	38,613		30	38,583
Redemption of Operating Partnership Unit holders	(177)		1	721	(37)		(862)
Share-based compensation, net of shares withheld for employee taxes	5,286		2	5,284
Dividends declared to common shareholders	(21,670)				(21,670)
Dividends declared to preferred shareholders	(5,026)				(5,026)
Distributions declared to noncontrolling interests	(505)						(505)
Dividends declared to deferred shares	(423)				(423)
Other comprehensive income - gain (loss) adjustment	7,906					7,727	179
Net income (loss)	80,836				78,993		1,843
Ending balance at Sep. 30, 2021	906,209	92,427	834	1,218,903	(419,180)	(6,405)	19,630
Beginning balance at Jun. 30, 2021	849,502	92,427	802	1,177,262	(433,360)	(7,581)	19,952
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares, net of issuance costs	38,899		30	38,869
Redemption of Operating Partnership Unit holders	0		1	721	0		(722)
Share-based compensation, net of shares withheld for employee taxes	2,052		1	2,051
Dividends declared to common shareholders	(9,644)				(9,644)
Dividends declared to preferred shareholders	(1,676)				(1,676)
Distributions declared to noncontrolling interests	(220)						(220)
Dividends declared to deferred shares	(202)				(202)
Other comprehensive income - gain (loss) adjustment	1,201					1,176	25
Net income (loss)	26,297				25,702		595
Ending balance at Sep. 30, 2021	$ 906,209	$ 92,427	$ 834	$ 1,218,903	$ (419,180)	$ (6,405)	$ 19,630