Consolidated Statement Of Shareholders' Equity - USD ($) $ in Thousands	Total	downREIT OP units	5.417% Series 1 Cumulative Convertible Preferred	Preferred Shares	Preferred Shares 5.417% Series 1 Cumulative Convertible Preferred	Common shares	Common shares downREIT OP units	Common shares 5.417% Series 1 Cumulative Convertible Preferred	Additional Paid-in Capital	Additional Paid-in Capital downREIT OP units	Additional Paid-in Capital 5.417% Series 1 Cumulative Convertible Preferred	Accumulated Dividends in Excess of Net Income	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	Noncontrolling Interests downREIT OP units
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, excluding amount attributable to redeemable noncontrolling interests	133,660											131,706		1,954
Other comprehensive income (loss) - change in value of interest rate swaps, excluding amounts attributable to redeemable noncontrolling interests	(4,831)												(4,831)
Dividends declared to common shareholders	(320,302)											(320,302)
Dividends declared to preferred shareholders	(8,042)											(8,042)
Distributions declared to noncontrolling interests, excluding amounts attributable to redeemable noncontrolling interests	(8,874)													(8,874)
Common shares issued, net (in shares)						1,080,882
Common shares issued, net	$ 98,839					$ 11			98,828
Shares issued under dividend reinvestment plan (in shares)	24,491					24,491
Shares issued under dividend reinvestment plan	$ 2,072								2,072
Share-based compensation expense, net of forfeitures (in shares)						114,251
Share-based compensation expense, net of forfeitures	13,243					$ 1			13,242
Shares withheld for employee taxes (in shares)						(33,034)
Shares withheld for employee taxes	(4,052)								(4,052)
Conversion and redemption of downREIT OP units							0
Conversion and redemption of downREIT OP units							$ 0			$ (30)
Contributions from noncontrolling interests, excluding amounts attributable to redeemable noncontrolling interests	120													120
Purchase of noncontrolling interest	(7,321)	$ (3,320)							(1,210)					(6,111)	$ (3,290)
Adjustment to redeemable noncontrolling interests	21,933								21,933
Ending balance (in shares) at Dec. 31, 2020				405,896		76,727,394
Ending 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, excluding amount attributable to redeemable noncontrolling interests	264,785											261,498		3,287
Other comprehensive income (loss) - change in value of interest rate swaps, excluding amounts attributable to redeemable noncontrolling interests	3,597												3,597
Dividends declared to common shareholders	(332,116)											(332,116)
Dividends declared to preferred shareholders	(8,042)											(8,042)
Distributions declared to noncontrolling interests, excluding amounts attributable to redeemable noncontrolling interests	(4,341)													(4,341)
Common shares issued, net (in shares)						1,643,845
Common shares issued, net	$ 172,753					$ 17			172,736
Shares issued under dividend reinvestment plan (in shares)	19,758					19,758
Shares issued under dividend reinvestment plan	$ 1,955								1,955
Share-based compensation expense, net of forfeitures (in shares)						164,553
Share-based compensation expense, net of forfeitures	14,434					$ 2			14,432
Shares withheld for employee taxes (in shares)						(29,031)
Shares withheld for employee taxes	(2,998)								(2,998)
Conversion and redemption of downREIT OP units							76,786
Conversion and redemption of downREIT OP units										7,474
Contributions from noncontrolling interests, excluding amounts attributable to redeemable noncontrolling interests	6,583													6,583
Purchase of noncontrolling interest		(99)													(7,573)
Adjustment to redeemable noncontrolling interests	(2,110)								(2,110)
Ending balance (in shares) at Dec. 31, 2021				405,896		78,603,305
Ending balance at Dec. 31, 2021	2,663,148			$ 159,997		$ 790			3,488,794			(1,066,932)	(2,047)	82,546
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income, excluding amount attributable to redeemable noncontrolling interests	389,048											385,491		3,557
Other comprehensive income (loss) - change in value of interest rate swaps, excluding amounts attributable to redeemable noncontrolling interests	7,804												7,804
Dividends declared to common shareholders	(344,711)											(344,711)
Dividends declared to preferred shareholders	(8,034)											(8,034)
Distributions declared to noncontrolling interests, excluding amounts attributable to redeemable noncontrolling interests	(5,007)													(5,007)
Common shares issued, net (in shares)						2,634,223
Common shares issued, net	306,854					$ 26			306,828
Exercise of stock options						366
Exercise of stock options	$ 35								35
Shares issued under dividend reinvestment plan (in shares)	19,502					19,502
Shares issued under dividend reinvestment plan	$ 2,104								2,104
Share-based compensation expense, net of forfeitures (in shares)						110,395
Share-based compensation expense, net of forfeitures	15,018					$ 2			15,016
Shares withheld for employee taxes (in shares)						(41,105)
Shares withheld for employee taxes	(4,900)								(4,900)
Conversion of preferred shares					(7,018)
Conversion of preferred shares					$ (175)
Conversion of preferred shares								1,675
Conversion of preferred shares			$ 0								$ 175
Conversion and redemption of downREIT OP units							14,598
Conversion and redemption of downREIT OP units							$ 0			$ 1,367
Purchase of noncontrolling interest		$ (698)													$ (2,065)
Deconsolidation of VIE	972													972
Adjustment to redeemable noncontrolling interests	12,382								12,382
Ending balance (in shares) at Dec. 31, 2022				398,878		81,342,959
Ending balance at Dec. 31, 2022	$ 3,034,015			$ 159,822		$ 818			$ 3,821,801			$ (1,034,186)	$ 5,757	$ 80,003