Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Treasury Stock	Distributions in Excess of Cumulative Net Income	Stockholders’ Investment	Nonredeemable Noncontrolling Interests
Beginning balance at Dec. 31, 2016	$ 2,514,240	$ 1,717	$ 100,936	$ 3,715,391	$ (148,373)	$ (1,214,114)	$ 2,455,557	$ 58,683
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	219,959					216,275	216,275	3,684
Common stock offering, net of issuance costs	211,774		6,250	205,524			211,774
Common stock issuance pursuant to stock based compensation	124		100	24			124
Spin-off of Parkway, Inc.	545					545	545
Common stock redemption by unit holders	0		301	9,767			10,068	(10,068)
Amortization of stock options and restricted stock, net of forfeitures	1,983			1,983			1,983
Contributions from nonredeemable noncontrolling interests	2,646							2,646
Distributions to nonredeemable noncontrolling interests	(1,807)							(1,807)
Common dividends	(124,353)					(124,353)	(124,353)
Ending 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	80,765					79,164	79,164	1,601
Common stock issuance pursuant to stock based compensation	(567)		99	(566)	(100)		(567)
Amortization of stock options and restricted stock, net of forfeitures	2,257		(5)	2,262			2,257
Contributions from nonredeemable noncontrolling interests	3,205							3,205
Distributions to nonredeemable noncontrolling interests	(2,653)							(2,653)
Common dividends	(109,291)					(109,291)	(109,291)
Ending 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	152,683					150,418	150,418	2,265
Common stock issued in merger	1,598,189		41,576	1,556,613			1,598,189
Common stock issuance pursuant to stock based compensation	507		91	416			507
Amortization of stock options and restricted stock, net of forfeitures	2,468		(1)	2,469			2,468
Nonredeemable noncontrolling interests acquired in merger	5,329							5,329
Contributions from nonredeemable noncontrolling interests	8,087							8,087
Distributions to nonredeemable noncontrolling interests	(2,411)							(2,411)
Common dividends	(158,173)					(158,173)	(158,173)
Ending balance at Dec. 31, 2019	$ 4,427,835	$ 1,717	$ 149,347	$ 5,493,883	$ (148,473)	$ (1,137,200)	$ 4,359,274	$ 68,561