CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Preferred Shares	Common Stock	Additional Paid-in-Capital	Accumulated Distributions in Excess of Net Income	Accumulated Other Comprehensive Income (Loss)	Non-controlling Interests
Beginning Balance at Dec. 31, 2018	$ 1,346,678	$ 94,016	$ 24	$ 2,772,855	$ (1,537,100)	$ 76	$ 16,807
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of noncontrolling OP units for common shares				156			(156)
Issuance of common shares and deferred compensation amortization, net	1,710			1,710
Repurchase of common shares	(958)			(958)
Repurchase of common shares to settle tax obligations	(3,942)		(1)	(3,941)
Forfeiture of employee common shares	5				5
Dividends/distributions	(26,363)				(25,471)		(892)
Net income	28,280				28,027		253
Other comprehensive loss	(76)					(76)
Ending Balance at Mar. 31, 2019	1,345,334	94,016	23	2,769,822	(1,534,539)	0	16,012
Beginning Balance at Dec. 31, 2019	1,724,719	94,016	25	2,976,670	(1,363,676)	(1,928)	19,612
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of noncontrolling OP units for common shares				428			(428)
Issuance of partnership interest in real estate	421						421
Issuance of common shares and deferred compensation amortization, net	18,931		1	18,930
Repurchase of common shares	(11,042)			(11,042)
Repurchase of common shares to settle tax obligations	(2,623)			(2,623)
Forfeiture of employee common shares	1			0	1
Dividends/distributions	(29,161)				(28,765)		(396)
Net income	18,420				18,154		266
Other comprehensive loss	(16,996)					(16,996)
Ending Balance at Mar. 31, 2020	$ 1,702,670	$ 94,016	$ 26	$ 2,982,363	$ (1,374,286)	$ (18,924)	$ 19,475