Condensed Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Treasury Stock	Distributions in Excess of Net Income	Stockholders’ Investment	Nonredeemable Noncontrolling Interests
Beginning balance at Dec. 31, 2017	$ 2,825,111	$ 1,717	$ 107,587	$ 3,932,689	$ (148,373)	$ (1,121,647)	$ 2,771,973	$ 53,138
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	58,014					56,804	56,804	1,210
Common stock issued pursuant to stock based compensation	(567)		99	(566)	(100)		(567)
Amortization of stock options and restricted stock, net of forfeitures	1,683		(5)	1,688			1,683
Contributions from nonredeemable noncontrolling interests	1,960							1,960
Distributions to nonredeemable noncontrolling interests	(2,071)							(2,071)
Common dividends	(82,004)					(82,004)	(82,004)
Ending balance at Sep. 30, 2018	2,824,455	1,717	107,681	3,933,811	(148,473)	(1,124,518)	2,770,218	54,237
Beginning balance at Jun. 30, 2018	2,832,344	1,717	107,683	3,933,248	(148,473)	(1,116,640)	2,777,535	54,809
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	19,859					19,485	19,485	374
Amortization of stock options and restricted stock, net of forfeitures	561		(2)	563			561
Contributions from nonredeemable noncontrolling interests	252							252
Distributions to nonredeemable noncontrolling interests	(1,198)							(1,198)
Common dividends	(27,363)					(27,363)	(27,363)
Ending balance at Sep. 30, 2018	2,824,455	1,717	107,681	3,933,811	(148,473)	(1,124,518)	2,770,218	54,237
Beginning balance at Dec. 31, 2018	2,821,156	1,717	107,681	3,934,385	(148,473)	(1,129,445)	2,765,865	55,291
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	34,115					33,306	33,306	809
Common stock issued in merger	1,598,189		41,576	1,556,613			1,598,189
Common stock issued pursuant to stock based compensation	510		91	419			510
Amortization of stock options and restricted stock, net of forfeitures	1,847		(1)	1,848			1,847
Nonredeemable noncontrolling interests acquired in merger	5,348							5,348
Contributions from nonredeemable noncontrolling interests	5,271							5,271
Distributions to nonredeemable noncontrolling interests	(1,745)							(1,745)
Common dividends	(115,613)					(115,613)	(115,613)
Ending balance at Sep. 30, 2019	4,349,078	1,717	149,347	5,493,265	(148,473)	(1,211,752)	4,284,104	64,974
Beginning balance at Jun. 30, 2019	4,369,618	1,717	149,348	5,492,648	(148,473)	(1,189,567)	4,305,673	63,945
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	20,692					20,374	20,374	318
Amortization of stock options and restricted stock, net of forfeitures	616		(1)	617			616
Contributions from nonredeemable noncontrolling interests	1,191							1,191
Distributions to nonredeemable noncontrolling interests	(480)							(480)
Common dividends	(42,559)					(42,559)	(42,559)
Ending balance at Sep. 30, 2019	$ 4,349,078	$ 1,717	$ 149,347	$ 5,493,265	$ (148,473)	$ (1,211,752)	$ 4,284,104	$ 64,974