Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative effect	Shares of Beneficial Interest	Additional Paid in Capital	Distributions in Excess of Net Income	Distributions in Excess of Net Income Cumulative effect	Accumulated Other Comprehensive Income (Loss)	Total Shareholders’ Equity	Total Shareholders’ Equity Cumulative effect	Noncontrolling Interests in Subsidiaries
Balance (in shares) at Dec. 31, 2018			79,910
Balance at Dec. 31, 2018	$ 1,068,478	$ (906)	$ 799	$ 1,526,574	$ (469,085)	$ (906)	$ 9,839	$ 1,068,127	$ (906)	$ 351
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to the controlling interests	329,352				329,352			329,352
Unrealized gain (loss) on interest rate hedges	(13,498)						(13,498)	(13,498)
Distributions to noncontrolling interests	(8)									(8)
Dividends	(72,339)				(72,339)			(72,339)
Equity issuances, net of issuance costs (in shares)			145
Equity issuances, net of issuance costs	$ 3,681		$ 2	3,679				3,681
Shares issued under Dividend Reinvestment Program (in shares)	128		128
Shares issued under Dividend Reinvestment Program	$ 3,430		$ 1	3,429				3,430
Share grants, net of forfeitures and tax withholdings (in shares)			109
Share grants, net of forfeitures and tax withholdings	6,053		$ 1	6,052				6,053
Balance (in shares) at Sep. 30, 2019			80,292
Balance at Sep. 30, 2019	1,324,243		$ 803	1,539,734	(212,978)		(3,659)	1,323,900		343
Balance (in shares) at Jun. 30, 2019			80,082
Balance at Jun. 30, 2019	1,010,708		$ 801	1,532,497	(521,661)		(1,272)	1,010,365		343
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to the controlling interests	332,770				332,770			332,770
Unrealized gain (loss) on interest rate hedges	(2,387)						(2,387)	(2,387)
Dividends	(24,087)				(24,087)			(24,087)
Equity issuances, net of issuance costs (in shares)			145
Equity issuances, net of issuance costs	$ 3,681		$ 2	3,679				3,681
Shares issued under Dividend Reinvestment Program (in shares)	64		64
Shares issued under Dividend Reinvestment Program	$ 1,757		$ 0	1,757				1,757
Share grants, net of forfeitures and tax withholdings (in shares)			1
Share grants, net of forfeitures and tax withholdings	1,801		$ 0	1,801				1,801
Balance (in shares) at Sep. 30, 2019			80,292
Balance at Sep. 30, 2019	1,324,243		$ 803	1,539,734	(212,978)		(3,659)	1,323,900		343
Balance (in shares) at Dec. 31, 2019			82,099
Balance at Dec. 31, 2019	1,412,062		$ 821	1,592,487	(183,405)		1,823	1,411,726		336
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to the controlling interests	(4,643)				(4,643)			(4,643)
Unrealized gain (loss) on interest rate hedges	(34,582)						(34,582)	(34,582)
Distributions to noncontrolling interests	(11)									(11)
Dividends	(74,387)				(74,387)			(74,387)
Equity issuances, net of issuance costs (in shares)			46
Equity issuances, net of issuance costs	$ 1,242		$ 1	1,241				1,242
Shares issued under Dividend Reinvestment Program (in shares)	64		64
Shares issued under Dividend Reinvestment Program	$ 1,581		$ 1	1,580				1,581
Share grants, net of forfeitures and tax withholdings (in shares)			142
Share grants, net of forfeitures and tax withholdings	5,853		$ 1	5,852				5,853
Balance (in shares) at Sep. 30, 2020			82,351
Balance at Sep. 30, 2020	1,307,115		$ 824	1,601,160	(262,435)		(32,759)	1,306,790		325
Balance (in shares) at Jun. 30, 2020			82,327
Balance at Jun. 30, 2020	1,328,566		$ 823	1,598,620	(236,673)		(34,533)	1,328,237		329
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to the controlling interests	(956)				(956)			(956)
Unrealized gain (loss) on interest rate hedges	1,774						1,774	1,774
Distributions to noncontrolling interests	(4)									(4)
Dividends	(24,806)				(24,806)			(24,806)
Equity issuances, net of issuance costs	$ 0
Shares issued under Dividend Reinvestment Program (in shares)	23		23
Shares issued under Dividend Reinvestment Program	$ 516		$ 1	515				516
Share grants, net of forfeitures and tax withholdings (in shares)			1
Share grants, net of forfeitures and tax withholdings	2,025		$ 0	2,025				2,025
Balance (in shares) at Sep. 30, 2020			82,351
Balance at Sep. 30, 2020	$ 1,307,115		$ 824	$ 1,601,160	$ (262,435)		$ (32,759)	$ 1,306,790		$ 325