CONSOLIDATED STATEMENTS OF EQUITY - USD ($)	Series E Cumulative Redeemable Preferred Stock Preferred Stock	Series E Cumulative Redeemable Preferred Stock Cumulative dividends and distributions	Series E Cumulative Redeemable Preferred Stock	Series F Cumulative Redeemable Preferred Stock Preferred Stock	Series F Cumulative Redeemable Preferred Stock Cumulative dividends and distributions	Series F Cumulative Redeemable Preferred Stock	Common Stock	Additional Paid In Capital	Retained Earnings	Cumulative dividends and distributions	Noncontrolling Interest in Consolidated Joint Venture	Total
Beginning Balance at Dec. 31, 2017	$ 115,000,000			$ 75,000,000			$ 2,253,000	$ 2,679,221,000	$ 932,277,000	$ (1,270,013,000)	$ 48,440,000	$ 2,582,178,000
Beginning Balance (in shares) at Dec. 31, 2017	4,600,000			3,000,000			225,321,660
Increase (Decrease) in Stockholders' Equity
Amortization of deferred stock compensation								2,113,000				2,113,000
Issuance of restricted common stock, net							$ 3,000	(4,235,000)				(4,232,000)
Issuance of restricted common stock, net (in shares)							297,013
Forfeiture of restricted common stock (in shares)							(3,961)
Common stock distributions and distributions payable										(11,281,000)		(11,281,000)
Preferred stock dividends and dividends payable		$ (1,998,000)	$ (1,998,000)		$ (1,209,000)	$ (1,209,000)
Distributions to noncontrolling interest											(1,169,000)	(1,169,000)
Net income									36,016,000		2,439,000	38,455,000
Ending Balance at Mar. 31, 2018	$ 115,000,000			$ 75,000,000			$ 2,256,000	2,677,099,000	968,293,000	(1,284,501,000)	49,710,000	2,602,857,000
Ending Balance (in shares) at Mar. 31, 2018	4,600,000			3,000,000			225,614,712
Beginning Balance at Dec. 31, 2017	$ 115,000,000			$ 75,000,000			$ 2,253,000	2,679,221,000	932,277,000	(1,270,013,000)	48,440,000	2,582,178,000
Beginning Balance (in shares) at Dec. 31, 2017	4,600,000			3,000,000			225,321,660
Increase (Decrease) in Stockholders' Equity
Net income												181,303,000
Ending Balance at Sep. 30, 2018	$ 115,000,000			$ 75,000,000			$ 2,282,000	2,726,523,000	1,106,391,000	(1,313,741,000)	48,985,000	2,760,440,000
Ending Balance (in shares) at Sep. 30, 2018	4,600,000			3,000,000			228,247,062
Beginning Balance at Mar. 31, 2018	$ 115,000,000			$ 75,000,000			$ 2,256,000	2,677,099,000	968,293,000	(1,284,501,000)	49,710,000	2,602,857,000
Beginning Balance (in shares) at Mar. 31, 2018	4,600,000			3,000,000			225,614,712
Increase (Decrease) in Stockholders' Equity
Amortization of deferred stock compensation								2,966,000				2,966,000
Issuance of restricted common stock							$ 1,000	(1,000)
Issuance of restricted common stock (in shares)							49,513
Forfeiture of restricted common stock (in shares)							(824)
Common stock distributions and distributions payable										(11,413,000)		(11,413,000)
Preferred stock dividends and dividends payable		(1,998,000)	(1,998,000)		(1,209,000)	(1,209,000)
Distributions to noncontrolling interest											(1,475,000)	(1,475,000)
Net proceeds from sale of common stock							$ 26,000	44,315,000				44,341,000
Number of shares of common stock sold (in shares)							2,590,854
Net income									48,888,000		2,374,000	51,262,000
Ending Balance at Jun. 30, 2018	$ 115,000,000			$ 75,000,000			$ 2,283,000	2,724,379,000	1,017,181,000	(1,299,121,000)	50,609,000	2,685,331,000
Ending Balance (in shares) at Jun. 30, 2018	4,600,000			3,000,000			228,254,255
Increase (Decrease) in Stockholders' Equity
Amortization of deferred stock compensation								2,143,000				2,143,000
Forfeiture of restricted common stock (in shares)							(7,193)
Forfeiture of restricted common stock							$ (1,000)	1,000
Common stock distributions and distributions payable										(11,412,000)		(11,412,000)
Preferred stock dividends and dividends payable		(1,998,000)	(1,998,000)		(1,210,000)	(1,210,000)
Distributions to noncontrolling interest											(4,000,000)	(4,000,000)
Net income									89,210,000		2,376,000	91,586,000
Ending Balance at Sep. 30, 2018	$ 115,000,000			$ 75,000,000			$ 2,282,000	2,726,523,000	1,106,391,000	(1,313,741,000)	48,985,000	2,760,440,000
Ending Balance (in shares) at Sep. 30, 2018	4,600,000			3,000,000			228,247,062
Beginning Balance at Dec. 31, 2018	$ 115,000,000			$ 75,000,000			$ 2,282,000	2,728,684,000	1,182,722,000	(1,440,202,000)	47,685,000	2,711,171,000
Beginning Balance (in shares) at Dec. 31, 2018	4,600,000			3,000,000			228,246,247
Increase (Decrease) in Stockholders' Equity
Amortization of deferred stock compensation								2,221,000				2,221,000
Issuance of restricted common stock, net							$ 4,000	(4,439,000)				(4,435,000)
Issuance of restricted common stock, net (in shares)							345,132
Forfeiture of restricted common stock (in shares)							(3,932)
Common stock distributions and distributions payable										(11,429,000)		(11,429,000)
Preferred stock dividends and dividends payable		(1,998,000)	(1,998,000)		(1,209,000)	(1,209,000)
Distributions to noncontrolling interest											(1,950,000)	(1,950,000)
Net income									16,317,000		1,599,000	17,916,000
Ending Balance at Mar. 31, 2019	$ 115,000,000			$ 75,000,000			$ 2,286,000	2,726,466,000	1,199,039,000	(1,454,838,000)	47,334,000	2,710,287,000
Ending Balance (in shares) at Mar. 31, 2019	4,600,000			3,000,000			228,587,447
Beginning Balance at Dec. 31, 2018	$ 115,000,000			$ 75,000,000			$ 2,282,000	2,728,684,000	1,182,722,000	(1,440,202,000)	47,685,000	2,711,171,000
Beginning Balance (in shares) at Dec. 31, 2018	4,600,000			3,000,000			228,246,247
Increase (Decrease) in Stockholders' Equity
Net income												97,379,000
Ending Balance at Sep. 30, 2019	$ 115,000,000			$ 75,000,000			$ 2,249,000	2,681,754,000	1,274,039,000	(1,483,907,000)	48,384,000	2,712,519,000
Ending Balance (in shares) at Sep. 30, 2019	4,600,000			3,000,000			224,861,978
Beginning Balance at Mar. 31, 2019	$ 115,000,000			$ 75,000,000			$ 2,286,000	2,726,466,000	1,199,039,000	(1,454,838,000)	47,334,000	2,710,287,000
Beginning Balance (in shares) at Mar. 31, 2019	4,600,000			3,000,000			228,587,447
Increase (Decrease) in Stockholders' Equity
Amortization of deferred stock compensation								3,002,000				3,002,000
Issuance of restricted common stock (in shares)							51,840
Repurchase of outstanding common stock							$ (4,000)	(5,731,000)				(5,735,000)
Repurchase of outstanding common stock (in shares)							(432,464)
Common stock distributions and distributions payable										(11,411,000)		(11,411,000)
Preferred stock dividends and dividends payable		(1,998,000)	(1,998,000)		(1,209,000)	(1,209,000)
Distributions to noncontrolling interest											(788,000)	(788,000)
Net income									43,963,000		1,955,000	45,918,000
Ending Balance at Jun. 30, 2019	$ 115,000,000			$ 75,000,000			$ 2,282,000	2,723,737,000	1,243,002,000	(1,469,456,000)	48,501,000	2,738,066,000
Ending Balance (in shares) at Jun. 30, 2019	4,600,000			3,000,000			228,206,823
Increase (Decrease) in Stockholders' Equity
Amortization of deferred stock compensation								2,249,000				2,249,000
Repurchase of outstanding common stock							$ (33,000)	(44,232,000)				(44,265,000)
Repurchase of outstanding common stock (in shares)							(3,344,845)
Common stock distributions and distributions payable										(11,243,000)		(11,243,000)
Preferred stock dividends and dividends payable		$ (1,998,000)	$ (1,998,000)		$ (1,210,000)	$ (1,210,000)
Distributions to noncontrolling interest											(2,625,000)	(2,625,000)
Net income									31,037,000		2,508,000	33,545,000
Ending Balance at Sep. 30, 2019	$ 115,000,000			$ 75,000,000			$ 2,249,000	$ 2,681,754,000	$ 1,274,039,000	$ (1,483,907,000)	$ 48,384,000	$ 2,712,519,000
Ending Balance (in shares) at Sep. 30, 2019	4,600,000			3,000,000			224,861,978