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	$ 0	$ (5,349)	$ 5,794
Issuance of common shares related to stock plans	71	0	65	6	0	0	0	0	0
Issuance of common shares for cash offering	36,857	0	243	36,614	0	0	0		0
Stock-based compensation, net	(1,841)	0	0	2,649	0	8	0	(4,498)	0
Distributions to non-controlling interests	(37)	0	0	0	0	0	0	0	(37)
Dividends declared-common shares	(55,810)	0	0	0	(55,810)	0	0	0	0
Dividends declared-preferred shares	(5,578)	0	0	0	(5,578)	0	0	0	0
Comprehensive income	74,364	0	0	0	74,327	0		0	37
Ending Balance at Jun. 30, 2022	2,090,678	175,000	21,437	5,973,435	(4,079,844)	4,703	0	(9,847)	5,794
Beginning Balance at Dec. 31, 2021	2,042,652	175,000	21,129	5,934,166	(4,092,783)	4,695	0	(5,349)	5,794
Comprehensive income	150,359
Ending Balance at Sep. 30, 2022	2,117,435	175,000	21,437	5,974,001	(4,044,178)	4,865	9,782	(29,266)	5,794
Beginning Balance at Jun. 30, 2022	2,090,678	175,000	21,437	5,973,435	(4,079,844)	4,703	0	(9,847)	5,794
Issuance of common shares related to stock plans	6	0	0	6	0	0	0	0	0
Expenses for cash offering	(126)	0	0	(126)	0	0	0	0	0
Repurchase of common shares	(20,000)	0	0	0	0	0	0	(20,000)	0
Stock-based compensation, net	1,429	0	0	686	0	162	0	581	0
Distributions to non-controlling interests	(18)	0	0	0	0	0	0	0	(18)
Dividends declared-common shares	(27,740)	0	0	0	(27,740)	0	0	0	0
Dividends declared-preferred shares	(2,789)	0	0	0	(2,789)	0	0	0	0
Comprehensive income	75,995	0	0	0	66,195	0	9,782	0	18
Ending Balance at Sep. 30, 2022	2,117,435	175,000	21,437	5,974,001	(4,044,178)	4,865	9,782	(29,266)	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	13	0	0	13	0	0	0	0	0
Repurchase of common shares	(26,611)	0	0	0	0	0	0	(26,611)	0
Stock-based compensation, net	(1,151)	0	0	(6,370)	0	(84)	0	5,303	0
Distributions to non-controlling interests	(18)	0	0	0	0	0	0	0	(18)
Repurchase of OP units	(1,735)	0	0	4,059	0	0	0	0	(5,794)
Dividends declared-common shares	(54,586)	0	0	0	(54,586)	0	0	0	0
Dividends declared-preferred shares	(5,578)	0	0	0	(5,578)	0	0	0	0
Comprehensive income	21,742	0	0	0	20,637	0	1,087	0	18
Ending Balance at Jun. 30, 2023	2,024,698	175,000	21,437	5,971,918	(4,085,897)	4,941	10,125	(72,826)	0
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
Comprehensive income	72,314
Ending Balance at Sep. 30, 2023	2,046,717	175,000	21,437	5,972,902	(4,067,355)	5,053	12,055	(72,375)	0
Beginning Balance at Jun. 30, 2023	2,024,698	175,000	21,437	5,971,918	(4,085,897)	4,941	10,125	(72,826)	0
Issuance of common shares related to stock plans	7	0	0	7	0	0	0	0	0
Stock-based compensation, net	1,540	0	0	977	0	112	0	451	0
Dividends declared-common shares	(27,311)	0	0	0	(27,311)	0	0	0	0
Dividends declared-preferred shares	(2,789)	0	0	0	(2,789)	0	0	0	0
Comprehensive income	50,572	0	0	0	48,642	0	1,930	0	0
Ending Balance at Sep. 30, 2023	$ 2,046,717	$ 175,000	$ 21,437	$ 5,972,902	$ (4,067,355)	$ 5,053	$ 12,055	$ (72,375)	$ 0