Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Distributions in Excess of Net Income [Member]	Total Stockholders' Equity [Member]	Noncontrolling Interest Exchangeable Operating Partnership Units [Member]	Noncontrolling Interests in Limited Partners' Interest in Consolidated Partnerships [Member]	Noncontrolling Interest [Member]
Beginning balance at Dec. 31, 2019	$ 6,289,961	$ 1,676	$ (23,199)	$ 7,654,930	$ (11,997)	$ (1,408,062)	$ 6,213,348	$ 36,100	$ 40,513	$ 76,613
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(24,783)					(25,332)	(25,332)	(115)	664	549
Other comprehensive income (loss):
Other comprehensive income (loss) before reclassification	(16,064)				(14,938)		(14,938)	(67)	(1,059)	(1,126)
Amounts reclassified from accumulated other comprehensive loss	1,425				1,404		1,404	6	15	21
Deferred compensation plan, net			(698)	698
Restricted stock issued, net of amortization	3,764	1		3,763			3,764
Common stock repurchased for taxes withheld for stock based compensation, net	(5,188)			(5,188)			(5,188)
Common stock issued under dividend reinvestment plan	379			379			379
Common stock issued, net of issuance costs	125,773	19		125,754			125,773
Contributions from partners	100								100	100
Issuance of exchangeable operating partnership units	1,275							1,275		1,275
Distributions to partners	(1,164)								(1,164)	(1,164)
Cash dividends declared - common stock/unit	(100,243)					(99,788)	(99,788)	(455)		(455)
Ending Balance at Mar. 31, 2020	6,275,235	1,696	(23,897)	7,780,336	(25,531)	(1,533,182)	6,199,422	36,744	39,069	75,813
Beginning balance at Dec. 31, 2020	6,058,147	1,697	(24,436)	7,792,082	(18,625)	(1,765,806)	5,984,912	35,727	37,508	73,235
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	81,625					80,656	80,656	364	605	969
Other comprehensive income (loss):
Other comprehensive income (loss) before reclassification	5,525				5,162		5,162	25	338	363
Amounts reclassified from accumulated other comprehensive loss	1,035				951		951	4	80	84
Deferred compensation plan, net			(339)	339
Restricted stock issued, net of amortization	2,479	1		2,478			2,479
Common stock repurchased for taxes withheld for stock based compensation, net	(3,859)			(3,859)			(3,859)
Common stock issued under dividend reinvestment plan	376			376			376
Distributions to partners	(785)								(785)	(785)
Cash dividends declared - common stock/unit	(101,499)					(101,046)	(101,046)	(453)		(453)
Ending Balance at Mar. 31, 2021	$ 6,043,044	$ 1,698	$ (24,775)	$ 7,791,416	$ (12,512)	$ (1,786,196)	$ 5,969,631	$ 35,667	$ 37,746	$ 73,413