CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Preferred Shares [Member]	Common Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Distributions in Excess of Net Income [Member]	Deferred Compensation Obligation [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock at Cost [Member]	Non-Controlling Interests [Member]
Beginning Balance at Dec. 31, 2021	$ 2,042,652	$ 175,000	$ 21,129	$ 5,934,166	$ (4,092,783)	$ 4,695		$ (5,349)	$ 5,794
Issuance of common shares related to stock plans	69	0	65	4	0	0		0	0
Issuance of common shares for cash offering	33,781	0	223	33,558	0	0			0
Stock-based compensation, net	(3,627)	0	0	996	0	(24)		(4,599)	0
Distributions to non-controlling interests	(18)	0	0	0	0	0		0	(18)
Dividends declared-common shares	(27,905)	0	0	0	(27,905)	0		0	0
Dividends declared-preferred shares	(2,789)	0	0	0	(2,789)	0		0	0
Comprehensive income	13,955	0	0	0	13,937	0		0	18
Ending Balance at Mar. 31, 2022	2,056,118	175,000	21,417	5,968,724	(4,109,540)	4,671		(9,948)	5,794
Beginning Balance at Dec. 31, 2022	2,092,622	175,000	21,437	5,974,216	(4,046,370)	5,025	$ 9,038	(51,518)	5,794
Issuance of common shares related to stock plans	6	0		6	0	0	0	0	0
Repurchase of common shares	(26,611)	0	0	0	0	0	0	(26,611)	0
Stock-based compensation, net	(3,009)	0	0	(8,133)	0	30	0	5,094	0
Distributions to non-controlling interests	(18)	0	0	0	0	0	0	0	(18)
Dividends declared-common shares	(27,292)	0	0	0	(27,292)	0	0	0	0
Dividends declared-preferred shares	(2,789)	0	0	0	(2,789)	0	0	0	0
Comprehensive income	12,102	0	0	0	15,284	0	(3,200)	0	18
Ending Balance at Mar. 31, 2023	$ 2,045,011	$ 175,000	$ 21,437	$ 5,966,089	$ (4,061,167)	$ 5,055	$ 5,838	$ (73,035)	$ 5,794