Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Cumulative Dividends in excess of Earnings	Accumulated Other Comprehensive Income (Loss)	Total Stockholders' Equity	Noncontrolling Interest - Unit holders in Operating Partnership
Balance at Dec. 31, 2018	$ 1,669,632	$ 75,000	$ 1,122	$ 2,118,179	$ (584,979)	$ 4,481	$ 1,613,803	$ 55,829
Balance (in shares) at Dec. 31, 2018			112,165,786
Increase (Decrease) in Stockholders' Equity
Cumulative Effect of New Accoutning Principle in Period of Adoption	(214)				(214)		(214)
Proceeds from sales of common stock, net	384,865		$ 137	384,728			384,865
Proceeds from sales of common stock (in shares)			13,622,203
Dividends, Common Stock					(89,130)
Dividends							(89,130)
Dividends and Distributions, Net	(93,002)
Distribution Made to Limited Partner, Cash Distributions Declared								(3,872)
Non-cash compensation activity, net	3,418			523			151	3,267
Non-cash compensation activity (in shares)			131,026
Non-cash compensation activity (in excess of earnings)			$ (1)		(373)
Redemption of common units to common stock			$ 4	6,231			6,235	6,235
Redemption of common units to common stock (in shares)			453,930
Rebalancing of noncontrolling interest				(8,648)			(8,648)	8,648
Other comprehensive loss	(23,006)					(22,252)	(22,252)	(754)
Net income	21,559				20,937		20,937	622
Balance at Jun. 30, 2019	1,963,252	75,000	$ 1,264	2,501,013	(653,759)	(17,771)	1,905,747	57,505
Balance (in shares) at Jun. 30, 2019			126,372,945
Balance at Dec. 31, 2018	1,669,632	75,000	$ 1,122	2,118,179	(584,979)	4,481	1,613,803	55,829
Balance (in shares) at Dec. 31, 2018			112,165,786
Balance at Dec. 31, 2019	2,363,891	75,000	$ 1,428	2,970,553	(723,027)	(18,426)	2,305,528	58,363
Balance (in shares) at Dec. 31, 2019			142,815,593
Balance at Mar. 31, 2019	1,774,841	75,000	$ 1,182	2,266,695	(621,225)	(2,253)	1,719,399	55,442
Balance (in shares) at Mar. 31, 2019			118,174,102
Increase (Decrease) in Stockholders' Equity
Proceeds from sales of common stock, net	236,336		$ 82	236,254			236,336
Proceeds from sales of common stock (in shares)			8,180,794
Dividends, Common Stock					(46,296)
Dividends							(46,296)
Dividends and Distributions, Net	(48,622)
Distribution Made to Limited Partner, Cash Distributions Declared								(2,326)
Non-cash compensation activity, net	2,555			1,656			1,656	899
Non-cash compensation activity (in shares)			3,190
Non-cash compensation activity (in excess of earnings)			$ 0		0
Redemption of common units to common stock			$ 0	207			207	(207)
Redemption of common units to common stock (in shares)			14,859
Rebalancing of noncontrolling interest				(3,799)			(3,799)	3,799
Other comprehensive loss	(16,028)					(15,518)	(15,518)	(510)
Net income	14,170				13,762		13,762	408
Balance at Jun. 30, 2019	1,963,252	75,000	$ 1,264	2,501,013	(653,759)	(17,771)	1,905,747	57,505
Balance (in shares) at Jun. 30, 2019			126,372,945
Balance at Dec. 31, 2019	2,363,891	75,000	$ 1,428	2,970,553	(723,027)	(18,426)	2,305,528	$ 58,363
Balance (in shares) at Dec. 31, 2019			142,815,593
Increase (Decrease) in Stockholders' Equity
Redemption of common units to common stock (in shares)								0
Balance at Mar. 31, 2020	2,517,114	75,000	$ 1,487	3,142,495	(714,799)	(47,860)	2,456,323	$ 60,791
Balance (in shares) at Mar. 31, 2020			148,708,031
Balance at Dec. 31, 2019	2,363,891	75,000	$ 1,428	2,970,553	(723,027)	(18,426)	2,305,528	58,363
Balance (in shares) at Dec. 31, 2019			142,815,593
Increase (Decrease) in Stockholders' Equity
Proceeds from sales of common stock, net	172,656		$ 56	172,600			172,656
Proceeds from sales of common stock (in shares)			5,600,000
Dividends, Common Stock					(109,702)
Dividends							(109,702)
Dividends and Distributions, Net	(112,703)
Distribution Made to Limited Partner, Cash Distributions Declared								3,001
Non-cash compensation activity, net	4,319			1,112			723	3,596
Non-cash compensation activity (in shares)			77,798
Non-cash compensation activity (in excess of earnings)			$ (1)		(390)
Redemption of common units to common stock			$ 4	7,082			7,086	$ 7,086
Redemption of common units to common stock (in shares)			447,730					0
Rebalancing of noncontrolling interest				(3,184)			(3,184)	$ 3,184
Other comprehensive loss	(32,200)					(31,411)	(31,411)	(789)
Net income	84,354				82,349		82,349	2,005
Balance at Jun. 30, 2020	2,480,317	75,000	$ 1,489	3,148,163	(750,770)	(49,837)	2,424,045	56,272
Balance (in shares) at Jun. 30, 2020			148,941,121
Balance at Mar. 31, 2020	2,517,114	75,000	$ 1,487	3,142,495	(714,799)	(47,860)	2,456,323	60,791
Balance (in shares) at Mar. 31, 2020			148,708,031
Increase (Decrease) in Stockholders' Equity
Proceeds from sales of common stock, net	(67)		$ 0	(67)			(67)
Proceeds from sales of common stock (in shares)			0
Dividends, Common Stock					(54,880)
Dividends							(54,880)
Dividends and Distributions, Net	(56,985)
Distribution Made to Limited Partner, Cash Distributions Declared								(2,105)
Non-cash compensation activity, net	2,948			1,970			1,970	978
Non-cash compensation activity (in shares)			4,750
Non-cash compensation activity (in excess of earnings)			$ 0		0
Redemption of common units to common stock			$ 2	3,656			3,658	(3,658)
Redemption of common units to common stock (in shares)			228,340
Rebalancing of noncontrolling interest				109			109	(109)
Other comprehensive loss	(2,009)					(1,977)	(1,977)	(32)
Net income	19,316				18,909		18,909	407
Balance at Jun. 30, 2020	$ 2,480,317	$ 75,000	$ 1,489	$ 3,148,163	$ (750,770)	$ (49,837)	$ 2,424,045	$ 56,272
Balance (in shares) at Jun. 30, 2020			148,941,121