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
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]
Adoption of new accounting standard	(510)				(510)
Net income (loss), excluding amounts attributable to redeemable noncontrolling interests	66,143				65,270		873
Other comprehensive (loss) income - change in fair value of interest rate swaps	(6,945)					(6,945)
Dividends declared to common shareholders	(158,810)				(158,810)
Dividends declared to preferred shareholders	(4,021)				(4,021)
Distributions declared to noncontrolling interests, excluding $1,735 attributable to redeemable noncontrolling interests	(1,677)						(1,677)
Shares issued (in shares)			29
Shares issued	2		$ 0	2
Shares issued under dividend reinvestment plan (in shares)			10,605
Shares issued under dividend reinvestment plan	955			955
Share-based compensation expense, net of forfeitures (in shares)			114,092
Share-based compensation expense, net of forfeitures	7,029		$ 1	7,028
Shares withheld for employee taxes (in shares)			(32,390)
Shares withheld for employee taxes	(3,997)			(3,997)
Conversion and redemption of OP units	(3,320)			(30)			(3,290)
Contributions from noncontrolling interests	120						120
Ending balance (in shares) at Jun. 30, 2020		405,896	75,633,140
Ending balance at Jun. 30, 2020	2,531,101	$ 159,997	$ 760	3,170,480	(889,195)	(7,758)	96,817
Beginning balance (in shares) at Mar. 31, 2020		405,896	75,622,504
Beginning balance at Mar. 31, 2020	2,599,608	$ 159,997	$ 760	3,166,899	(818,284)	(7,265)	97,501
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss), excluding amounts attributable to redeemable noncontrolling interests	10,717				10,507		210
Other comprehensive (loss) income - change in fair value of interest rate swaps	(493)					(493)
Dividends declared to common shareholders	(79,407)				(79,407)
Dividends declared to preferred shareholders	(2,011)				(2,011)
Distributions declared to noncontrolling interests, excluding $1,735 attributable to redeemable noncontrolling interests	(894)						(894)
Shares issued (in shares)			16
Shares issued	0		$ 0	0
Shares issued under dividend reinvestment plan (in shares)			6,771
Shares issued under dividend reinvestment plan	509			509
Share-based compensation expense, net of forfeitures (in shares)			4,026
Share-based compensation expense, net of forfeitures	3,087		$ 0	3,087
Shares withheld for employee taxes (in shares)			(177)
Shares withheld for employee taxes	(15)			(15)
Ending balance (in shares) at Jun. 30, 2020		405,896	75,633,140
Ending balance at Jun. 30, 2020	2,531,101	$ 159,997	$ 760	3,170,480	(889,195)	(7,758)	96,817
Beginning balance (in shares) at Dec. 31, 2020		405,896	76,727,394
Beginning balance at Dec. 31, 2020	2,548,747	$ 159,997	$ 771	3,297,305	(988,272)	(5,644)	84,590
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss), excluding amounts attributable to redeemable noncontrolling interests	95,921				94,440		1,481
Other comprehensive income - change in fair value of interest rate swaps, excluding portion attributable to redeemable noncontrolling interest	2,406					2,406
Dividends declared to common shareholders	(164,788)				(164,788)
Dividends declared to preferred shareholders	(4,021)				(4,021)
Distributions declared to noncontrolling interests, excluding $1,735 attributable to redeemable noncontrolling interests	(1,727)						(1,727)
Shares issued (in shares)			847,509
Shares issued	87,133		$ 9	87,124
Shares issued under dividend reinvestment plan (in shares)			11,516
Shares issued under dividend reinvestment plan	1,019			1,019
Share-based compensation expense, net of forfeitures (in shares)			152,185
Share-based compensation expense, net of forfeitures	7,507		$ 2	7,505
Shares withheld for employee taxes (in shares)			(27,500)
Shares withheld for employee taxes	(2,813)			(2,813)
Conversion and redemption of OP units (in Shares)			49,484
Conversion and redemption of OP units	(99)		$ 0	5,049			(5,148)
Contributions from noncontrolling interests	6,554						6,554
Ending balance (in shares) at Jun. 30, 2021		405,896	77,760,588
Ending balance at Jun. 30, 2021	2,575,839	$ 159,997	$ 782	3,395,189	(1,062,641)	(3,238)	85,750
Beginning balance (in shares) at Mar. 31, 2021		405,896	77,706,466
Beginning balance at Mar. 31, 2021	2,604,960	$ 159,997	$ 781	3,386,917	(1,024,417)	(2,300)	83,982
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss), excluding amounts attributable to redeemable noncontrolling interests	46,990				46,204		786
Other comprehensive income - change in fair value of interest rate swaps, excluding portion attributable to redeemable noncontrolling interest	(938)
Other comprehensive (loss) income - change in fair value of interest rate swaps						(938)
Dividends declared to common shareholders	(82,417)				(82,417)
Dividends declared to preferred shareholders	(2,011)				(2,011)
Distributions declared to noncontrolling interests, excluding $1,735 attributable to redeemable noncontrolling interests	(943)						(943)
Shares issued (in shares)			16
Shares issued	(81)		$ 1	(82)
Shares issued under dividend reinvestment plan (in shares)			5,236
Shares issued under dividend reinvestment plan	474			474
Share-based compensation expense, net of forfeitures (in shares)			4,473
Share-based compensation expense, net of forfeitures	3,358		$ 0	3,358
Shares withheld for employee taxes (in shares)			(71)
Shares withheld for employee taxes	(8)			(8)
Conversion and redemption of OP units (in Shares)			44,468
Conversion and redemption of OP units	(99)		$ 0	4,530			(4,629)
Contributions from noncontrolling interests	6,554						6,554
Ending balance (in shares) at Jun. 30, 2021		405,896	77,760,588
Ending balance at Jun. 30, 2021	$ 2,575,839	$ 159,997	$ 782	$ 3,395,189	$ (1,062,641)	$ (3,238)	$ 85,750