CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Thousands, $ 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 Loss [Member]	Treasury Stock at Cost [Member]	Non-Controlling Interests [Member]
Beginning Balance at Dec. 31, 2017	$ 2,897,438	$ 525,000	$ 18,426	$ 5,531,249	$ (3,183,134)	$ 8,777	$ (1,106)	$ (8,280)	$ 6,506
Beginning Balance, shares at Dec. 31, 2017			184,256
Issuance of common shares related to stock plans	6,316	0	$ 45	5,928	0	0	0	343	0
Issuance of common shares related to stock plans, shares			456
Repurchase of common shares	(36,341)	0	$ 0	0	0	0	0	(36,341)	0
Stock-based compensation, net	5,579	0	$ 0	6,163	0	(584)	0	0	0
Stock-based compensation, net, shares			0
Distributions to non-controlling interests	(3,548)	0	$ 0	0	0	0	0	0	(3,548)
Redemption of OP Units	(709)	0	0	880	0	0	0	0	(1,589)
Dividends declared- common shares	(214,514)	0	0	0	(214,514)	0	0	0	0
Dividends declared- preferred shares	(33,531)	0	0	0	(33,531)	0	0	0	0
RVI spin-off	(663,406)	0	0	0	(663,406)	0	0	0	0
Comprehensive (loss) income	115,718	0	0	0	114,434	0	(275)	0	1,559
Ending Balance at Dec. 31, 2018	2,073,002	525,000	$ 18,471	5,544,220	(3,980,151)	8,193	(1,381)	(44,278)	2,928
Ending Balance, shares at Dec. 31, 2018			184,712
Issuance of common shares related to stock plans	2,074	0	$ 3	145	0	0	0	1,926	0
Issuance of common shares related to stock plans, shares			30
Issuance of common shares for cash offering	$ 194,670	0	$ 908	145,048	0	0	0	48,714	0
Issuance of common shares for cash offering, shares	13,225		9,081
Repurchase of common shares	$ (14,069)	0	$ 0	0	0	0	0	(14,069)	0
Redemption of preferred shares	(200,031)	(200,000)	0	7,145	(7,176)	0	0	0	0
Stock-based compensation, net	3,578	0	$ 0	3,842	0	(264)	0	0	0
Stock-based compensation, net, shares			0
Distributions to non-controlling interests	(990)	0	$ 0	0	0	0	0	0	(990)
Dividends declared- common shares	(147,674)	0	0	0	(147,674)	0	0	0	0
Dividends declared- preferred shares	(31,797)	0	0	0	(31,797)	0	0	0	0
Comprehensive (loss) income	102,715	0	0	0	100,699	0	890	0	1,126
Ending Balance at Dec. 31, 2019	1,981,478	325,000	$ 19,382	5,700,400	(4,066,099)	7,929	(491)	(7,707)	3,064
Ending Balance, shares at Dec. 31, 2019			193,823
Issuance of common shares related to stock plans	3,798	0	$ 18	(108)	0	0	0	3,888	0
Issuance of common shares related to stock plans, shares			172
Repurchase of common shares	(7,500)	0	$ 0	0	0	0	0	(7,500)	0
Stock-based compensation, net	2,422	0	$ 0	4,872	0	(2,450)	0	0	0
Stock-based compensation, net, shares			0
Distributions to non-controlling interests	(618)	0	$ 0	0	0	0	0	0	(618)
Dividends declared- common shares	(48,625)	0	0	0	(48,625)	0	0	0	0
Dividends declared- preferred shares	(20,531)	0	0	0	(20,531)	0	0	0	0
Comprehensive (loss) income	34,399	0	0	0	35,721	0	(2,191)	0	869
Ending Balance at Dec. 31, 2020	$ 1,944,823	$ 325,000	$ 19,400	$ 5,705,164	$ (4,099,534)	$ 5,479	$ (2,682)	$ (11,319)	$ 3,315
Ending Balance, shares at Dec. 31, 2020			193,995