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	55,426				54,763		663
Other comprehensive (loss) income - change in fair value of interest rate swaps	(6,452)					(6,452)
Dividends declared to common shareholders	(79,403)				(79,403)
Dividends declared to preferred shareholders	(2,010)				(2,010)
Distributions declared to noncontrolling interests	(783)						(783)
Shares issued (in shares)			13
Shares issued	2		$ 0	2
Shares issued under dividend reinvestment plan (in shares)			3,834
Shares issued under dividend reinvestment plan	446			446
Share-based compensation expense, net of forfeitures (in shares)			110,066
Share-based compensation expense, net of forfeitures	3,942		$ 1	3,941
Shares withheld for employee taxes (in shares)			(32,213)
Shares withheld for employee taxes	(3,982)			(3,982)
Conversion and redemption of OP units	(3,320)			(30)			(3,290)
Contributions from noncontrolling interests	120						120
Ending balance (in shares) at Mar. 31, 2020		405,896	75,622,504
Ending balance at Mar. 31, 2020	2,599,608	$ 159,997	$ 760	3,166,899	(818,284)	(7,265)	97,501
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	48,931				48,236		695
Other comprehensive income - change in fair value of interest rate swaps, excluding portion attributable to redeemable noncontrolling interest	3,344					3,344
Dividends declared to common shareholders	(82,371)				(82,371)
Dividends declared to preferred shareholders	(2,010)				(2,010)
Distributions declared to noncontrolling interests	(784)						(784)
Shares issued (in shares)			847,493
Shares issued	87,214		$ 8	87,206
Shares issued under dividend reinvestment plan (in shares)			6,280
Shares issued under dividend reinvestment plan	545			545
Share-based compensation expense, net of forfeitures (in shares)			147,712
Share-based compensation expense, net of forfeitures	4,149		$ 2	4,147
Shares withheld for employee taxes (in shares)			(27,429)
Shares withheld for employee taxes	(2,805)			(2,805)
Conversion and redemption of OP units (in Shares)			5,016
Conversion and redemption of OP units	0		$ 0	519			(519)
Ending balance (in shares) at Mar. 31, 2021		405,896	77,706,466
Ending balance at Mar. 31, 2021	$ 2,604,960	$ 159,997	$ 781	$ 3,386,917	$ (1,024,417)	$ (2,300)	$ 83,982