Consolidated Statement Of Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Shares	Common Shares	Additional Paid-in Capital	Accumulated Dividends in Excess of Net Income	Accumulated Other Comprehensive (Loss) Income	Noncontrolling Interests	Common Shares Additional Paid-in Capital
Beginning balance (in shares) at Dec. 31, 2018		405,896	74,249,633
Beginning balance at Dec. 31, 2018	$ 2,467,330	$ 159,997	$ 745	$ 3,004,442	$ (818,877)	$ (416)	$ 121,439
Increase (Decrease) in Stockholders' Equity [Roll Forward]
January 1st adoption of new accounting standard	(7,098)				(7,098)
Net income (loss), excluding amounts attributable to redeemable noncontrolling interests	208,972				206,511		2,461
Other comprehensive (loss) income - change in fair value of interest rate swaps	(719)					(719)
Dividends declared to common shareholders	(231,657)				(231,657)
Dividends declared to preferred shareholders	(6,031)				(6,031)
Distributions declared to noncontrolling interests	(8,812)						(8,812)
Shares issued (in shares)			1,045,470
Shares issued	139,499		$ 11					$ 139,488
Shares issued under dividend reinvestment plan (in shares)			12,006
Shares issued under dividend reinvestment plan	1,567			1,567
Share-based compensation expense, net of forfeitures (in shares)			110,804
Share-based compensation expense, net of forfeitures	10,143		$ 1	10,142
Shares withheld for employee taxes (in shares)			(34,234)
Shares withheld for employee taxes	(4,615)			(4,615)
Conversion and redemption of OP units (in Shares)			111,252
Conversion and redemption of OP units	(72)		$ 1	11,933			(12,006)
Contributions from noncontrolling interests	111						111
Adjustment to redeemable noncontrolling interests	4,503			4,503
Ending balance (in shares) at Sep. 30, 2019		405,896	75,494,931
Ending balance at Sep. 30, 2019	2,573,121	$ 159,997	$ 758	3,167,460	(857,152)	(1,135)	103,193
Beginning balance (in shares) at Jun. 30, 2019		405,896	74,950,197
Beginning balance at Jun. 30, 2019	2,510,646	$ 159,997	$ 752	3,088,946	(841,505)	(1,024)	103,480
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss), excluding amounts attributable to redeemable noncontrolling interests	66,285				65,465		820
Other comprehensive (loss) income - change in fair value of interest rate swaps	(111)					(111)
Dividends declared to common shareholders	(79,102)				(79,102)
Dividends declared to preferred shareholders	(2,010)				(2,010)
Distributions declared to noncontrolling interests	(1,148)						(1,148)
Shares issued (in shares)			533,516
Shares issued	71,195		$ 6					71,189
Shares issued under dividend reinvestment plan (in shares)			3,885
Shares issued under dividend reinvestment plan	513			513
Share-based compensation expense, net of forfeitures (in shares)			8,667
Share-based compensation expense, net of forfeitures	3,151		$ 0	3,151
Shares withheld for employee taxes (in shares)			(1,334)
Shares withheld for employee taxes	(173)			(173)
Conversion and redemption of OP units (in Shares)			0
Conversion and redemption of OP units	(72)		$ 0	(2)			(70)
Contributions from noncontrolling interests	111						111
Adjustment to redeemable noncontrolling interests	3,836			3,836
Ending balance (in shares) at Sep. 30, 2019		405,896	75,494,931
Ending balance at Sep. 30, 2019	2,573,121	$ 159,997	$ 758	3,167,460	(857,152)	(1,135)	103,193
Beginning balance (in shares) at Dec. 31, 2019		405,896	75,540,804
Beginning balance at Dec. 31, 2019	2,636,132	$ 159,997	$ 759	3,166,522	(791,124)	(813)	100,791
Increase (Decrease) in Stockholders' Equity [Roll Forward]
January 1st adoption of new accounting standard	(510)				(510)
Net income (loss), excluding amounts attributable to redeemable noncontrolling interests	32,050				36,981		(4,931)
Other comprehensive (loss) income - change in fair value of interest rate swaps	(6,487)					(6,487)
Dividends declared to common shareholders	(238,980)				(238,980)
Dividends declared to preferred shareholders	(6,031)				(6,031)
Distributions declared to noncontrolling interests	(2,465)						(2,465)
Shares issued (in shares)			57
Shares issued	5		$ 0					5
Shares issued under dividend reinvestment plan (in shares)			17,669
Shares issued under dividend reinvestment plan	1,461			1,461
Share-based compensation expense, net of forfeitures (in shares)			115,368
Share-based compensation expense, net of forfeitures	10,144		$ 1	10,143
Shares withheld for employee taxes (in shares)			(32,824)
Shares withheld for employee taxes	(4,035)			(4,035)
Conversion and redemption of OP units (in Shares)			0
Conversion and redemption of OP units	(3,320)		$ 0	(30)			(3,290)
Contributions from noncontrolling interests	120						120
Ending balance (in shares) at Sep. 30, 2020		405,896	75,641,074
Ending balance at Sep. 30, 2020	2,418,084	$ 159,997	$ 760	3,174,066	(999,664)	(7,300)	90,225
Beginning balance (in shares) at Jun. 30, 2020		405,896	75,633,140
Beginning balance at Jun. 30, 2020	2,531,101	$ 159,997	$ 760	3,170,480	(889,195)	(7,758)	96,817
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss), excluding amounts attributable to redeemable noncontrolling interests	(34,093)				(28,289)		(5,804)
Other comprehensive (loss) income - change in fair value of interest rate swaps	458					458
Dividends declared to common shareholders	(80,170)				(80,170)
Dividends declared to preferred shareholders	(2,010)				(2,010)
Distributions declared to noncontrolling interests	(788)						(788)
Shares issued (in shares)			28
Shares issued	3		$ 0					$ 3
Shares issued under dividend reinvestment plan (in shares)			7,064
Shares issued under dividend reinvestment plan	506			506
Share-based compensation expense, net of forfeitures (in shares)			1,276
Share-based compensation expense, net of forfeitures	3,115		$ 0	3,115
Shares withheld for employee taxes (in shares)			(434)
Shares withheld for employee taxes	(38)			(38)
Ending balance (in shares) at Sep. 30, 2020		405,896	75,641,074
Ending balance at Sep. 30, 2020	$ 2,418,084	$ 159,997	$ 760	$ 3,174,066	$ (999,664)	$ (7,300)	$ 90,225