CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Total Stockholders’ Equity	Preferred Stock	Common Stock	Additional Paid-in Capital	Cumulative Distributions in Excess of Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Beginning Balance at Dec. 31, 2018	$ 1,908,423	$ 1,876,094	$ 159,094	$ 966	$ 1,798,113	$ (88,341)	$ 6,262	$ 32,329
Beginning Balance (in shares) at Dec. 31, 2018				96,810,504
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption of ASC 842	(222)	(222)				(222)
Issuance of common stock (in shares)				7,148,746
Issuance of common stock	248,394	248,394		$ 71	248,323
Offering costs	(3,974)	(3,974)	0		(3,974)
Share-based compensation (in shares)				86,919
Share-based compensation	2,613	511		$ 1	510			2,102
Shares acquired to satisfy employee tax withholding requirements on vesting restricted stock (in shares)				(23,090)
Shares acquired to satisfy employee tax withholding requirements on vesting restricted stock	(791)	(791)			(791)
Conversion of units to common stock (in shares)				4,967
Conversion of units to common stock	0	37			37			(37)
Net income	10,717	10,516	2,423			8,093		201
Other comprehensive income (loss)	(5,127)	(5,001)					(5,001)	(126)
Preferred stock dividends	(2,423)	(2,423)	(2,423)
Common stock dividends	(19,245)	(19,245)				(19,245)
Distributions	(529)							(529)
Ending Balance at Mar. 31, 2019	2,137,836	2,103,896	159,094	$ 1,038	2,042,218	(99,715)	1,261	33,940
Ending Balance (in shares) at Mar. 31, 2019				104,028,046
Beginning Balance at Dec. 31, 2019	$ 2,622,449	2,556,177	242,327	$ 1,136	2,439,007	(118,751)	(7,542)	66,272
Beginning Balance (in shares) at Dec. 31, 2019	113,793,300			113,793,300
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)	2,206,957			2,206,957
Issuance of common stock	$ 80,814	80,814		$ 22	80,792
Offering costs	(1,383)	(1,383)	0		(1,383)
Issuance of 4.00% cumulative redeemable convertible preferred units	63,277							63,277
Noncontrolling Interest, Increase from Subsidiary Equity Issuance, Preferred	40,787							40,787
Share-based compensation (in shares)				102,275
Share-based compensation	3,627	699		$ 1	698			2,928
Shares acquired to satisfy employee tax withholding requirements on vesting restricted stock (in shares)				(25,797)
Shares acquired to satisfy employee tax withholding requirements on vesting restricted stock	(1,207)	(1,207)			(1,207)
Conversion of units to common stock (in shares)				254,612
Conversion of units to common stock	0	6,370		$ 3	6,367			(6,370)
Net income	15,272	14,555	3,636			10,919		717
Other comprehensive income (loss)	(14,968)	(14,408)					(14,408)	(560)
Preferred stock dividends	(3,636)	(3,636)	(3,636)
Preferred unit distributions	(423)							(423)
Common stock dividends	(25,011)	(25,011)				(25,011)
Distributions	(920)							(920)
Ending Balance at Mar. 31, 2020	$ 2,778,678	$ 2,612,970	$ 242,327	$ 1,162	$ 2,524,274	$ (132,843)	$ (21,950)	$ 165,708
Ending Balance (in shares) at Mar. 31, 2020	116,331,347			116,331,347