CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Cumulative Effect of Change in Accounting Principle	Common Shares	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Distributions in Excess of Accumulated Earnings	Distributions in Excess of Accumulated Earnings Cumulative Effect of Change in Accounting Principle	Total Common Shareholders' Equity	Total Common Shareholders' Equity Cumulative Effect of Change in Accounting Principle	Noncontrolling Interests		Noncontrolling Interests Cumulative Effect of Change in Accounting Principle
Balance at Dec. 31, 2019	$ 2,186,965		$ 87	$ 1,706,357	$ (31,175)	$ (132,961)		$ 1,542,308		$ 644,657
Balance (in Shares) at Dec. 31, 2019			87,050
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of Common Shares	$ (22,400)
Repurchase of Common Shares (in shares)	(1,219,065)
Balance at Mar. 31, 2020	$ 2,011,560		$ 86	1,686,794	(85,715)	(166,701)		1,434,464		577,096
Balance (in Shares) at Mar. 31, 2020			85,990
Balance at Dec. 31, 2019	2,186,965		$ 87	1,706,357	(31,175)	(132,961)		1,542,308		644,657
Balance (in Shares) at Dec. 31, 2019			87,050
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	0		$ 0	6,544	0	0		6,544		(6,544)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership (in Shares)			408
Repurchase of Common Shares	(22,386)		$ (1)	(22,385)	0	0		(22,386)		0
Repurchase of Common Shares (in shares)			(1,219)
Acquisition of noncontroling interest	588									588
Dividends/distributions declared	(26,909)					(24,937)		(24,937)		(1,972)
Employee and trustee stock compensation, net	6,136		$ 0	346	0	0		346		5,790
Employee and trustee stock compensation, net (in Shares)			26
Noncontrolling interest distributions	(4,536)									(4,536)
Noncontrolling interest contributions	28,309									28,309
Comprehensive income (loss)	(74,436)				(59,034)	10,996		(48,038)		(26,398)
Reallocation of noncontrolling interests	0			2,144	0	0		2,144		(2,144)	[1]
Balance at Jun. 30, 2020	2,093,331		$ 86	1,693,006	(90,209)	(147,291)		1,455,592		637,739
Balance (in Shares) at Jun. 30, 2020			86,265
Balance at Dec. 31, 2019	2,186,965		$ 87	1,706,357	(31,175)	(132,961)		1,542,308		644,657
Balance (in Shares) at Dec. 31, 2019			87,050
Balance at Dec. 31, 2020	$ 2,048,553	$ (400)	$ 86	1,683,165	(74,891)	(167,046)	$ (389)	1,441,314	$ (389)	607,239		$ (11)
Balance (in Shares) at Dec. 31, 2020	86,268,303		86,269
Balance at Mar. 31, 2020	$ 2,011,560		$ 86	1,686,794	(85,715)	(166,701)		1,434,464		577,096
Balance (in Shares) at Mar. 31, 2020			85,990
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	0		$ 0	4,072	0	0		4,072		(4,072)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership (in Shares)			260
Repurchase of Common Shares	(34)		$ 0	(34)	0	0		(34)		0
Repurchase of Common Shares (in shares)			0
Acquisition of noncontroling interest	588									588
Dividends/distributions declared	(123)									(123)
Employee and trustee stock compensation, net	2,317		$ 0	175	0	0		175		2,142
Employee and trustee stock compensation, net (in Shares)			15
Noncontrolling interest distributions	(1,418)									(1,418)
Noncontrolling interest contributions	21,041									21,041
Comprehensive income (loss)	59,400				(4,494)	19,410		14,916		44,484
Reallocation of noncontrolling interests	0			1,999	0	0		1,999		(1,999)	[1]
Balance at Jun. 30, 2020	2,093,331		$ 86	1,693,006	(90,209)	(147,291)		1,455,592		637,739
Balance (in Shares) at Jun. 30, 2020			86,265
Balance at Dec. 31, 2020	$ 2,048,553	$ (400)	$ 86	1,683,165	(74,891)	(167,046)	$ (389)	1,441,314	$ (389)	607,239		$ (11)
Balance (in Shares) at Dec. 31, 2020	86,268,303		86,269
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	$ 0		$ 0	409	0	0		409		(409)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership (in Shares)			26
Issuance of Common Shares	$ 45,677		$ 2	45,675	0	0		45,677		0
Issuance of Common Shares (in Shares)			2,072
Repurchase of Common Shares (in shares)	0
Dividends/distributions declared	$ (28,308)					(26,208)		(26,208)		(2,100)
Employee and trustee stock compensation, net	7,135		$ 0	687	0	0		687		6,448
Employee and trustee stock compensation, net (in Shares)			52
Noncontrolling interest distributions	(11,031)									(11,031)
Noncontrolling interest contributions	17,109									17,109
Comprehensive income (loss)	37,215				26,982	9,080		36,062		1,153
Reallocation of noncontrolling interests	0			750	0	0		750		(750)	[1]
Balance at Jun. 30, 2021	$ 2,116,350		$ 88	1,730,686	(47,909)	(184,174)		1,498,691		617,659
Balance (in Shares) at Jun. 30, 2021	88,419,303		88,419
Balance at Mar. 31, 2021	$ 2,084,369		$ 86	1,683,552	(41,962)	(174,829)		1,466,847		617,522
Balance (in Shares) at Mar. 31, 2021			86,302
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	0		$ 0	115	0	0		115		(115)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership (in Shares)			7
Issuance of Common Shares	45,677		$ 2	45,675	0	0		45,677		0
Issuance of Common Shares (in Shares)			2,072
Dividends/distributions declared	(14,315)		$ 0	0	0	(13,263)		(13,263)		(1,052)
Employee and trustee stock compensation, net	2,624		$ 0	225	0	0		225		2,399
Employee and trustee stock compensation, net (in Shares)			38
Noncontrolling interest distributions	(4,355)									(4,355)
Noncontrolling interest contributions	5,868									5,868
Comprehensive income (loss)	(3,518)				(5,947)	3,918		(2,029)		(1,489)
Reallocation of noncontrolling interests	0			1,119				1,119		(1,119)	[1]
Balance at Jun. 30, 2021	$ 2,116,350		$ 88	$ 1,730,686	$ (47,909)	$ (184,174)		$ 1,498,691		$ 617,659
Balance (in Shares) at Jun. 30, 2021	88,419,303		88,419

[1] Adjustment reflects the difference between the fair value of the consideration received or paid and the book value of the Common Shares, Common OP Units, Preferred OP Units, and LTIP Units involving changes in ownership.