Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Capital in Excess of Par Value	Distributions in Excess of Retained Earnings	Accumulated Other Comprehensive Loss	Total
Balance at Dec. 31, 2018	$ 2,211	$ 4,129,082	$ (267,651)	$ (141)	$ 3,863,501
Balance (in shares) at Dec. 31, 2018	221,071,838
Increase (Decrease) in Stockholders' Equity
Net income			45,556		45,556
Other comprehensive loss				(886)	(886)
Issuance of common stock, net of costs of $944 and $2,549, respectively	$ 50	158,258			158,308
Issuance of common stock, net of costs (shares)	4,978,510
Equity-based compensation	$ 2	1,683	14		1,699
Equity-based compensation (shares)	386,151
Shares repurchased under stock compensation plan		(2,773)	(1,535)		(4,308)
Shares repurchased under stock compensation plan (in shares)	(145,967)
Common dividends declared and dividend equivalents on restricted stock units			(74,715)		(74,715)
Balance at Mar. 31, 2019	$ 2,263	4,286,250	(298,331)	(1,027)	3,989,155
Balance (in shares) at Mar. 31, 2019	226,290,532
Increase (Decrease) in Stockholders' Equity
Adoption of ASC Topic 326, cumulative adjustment			(2,465)		(2,465)
Balance at Dec. 31, 2019	$ 2,398	4,787,932	(302,609)	(2,336)	4,485,385
Balance (in shares) at Dec. 31, 2019	239,822,900
Increase (Decrease) in Stockholders' Equity
Net income			62,660		62,660
Other comprehensive loss				(1,286)	(1,286)
Issuance of common stock, net of costs of $944 and $2,549, respectively	$ 41	148,536			148,577
Issuance of common stock, net of costs (shares)	4,127,800
Equity-based compensation	$ 3	(3,575)			(3,572)
Equity-based compensation (shares)	342,757
Shares repurchased under stock compensation plan		(2,745)	(2,340)		(5,085)
Shares repurchased under stock compensation plan (in shares)	(134,980)
Common dividends declared and dividend equivalents on restricted stock units			(85,505)		(85,505)
Balance at Mar. 31, 2020	$ 2,442	$ 4,930,148	$ (330,259)	$ (3,622)	$ 4,598,709
Balance (in shares) at Mar. 31, 2020	244,158,477