CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Thousands, $ in Thousands		Total	Common Stock	Additional Paid-In Capital	Cumulative Dividends In Excess Of Earnings	Accumulated Other Comprehensive Income (Loss)	Total Stockholders’ Equity	Noncontrolling Interests
Balance at Dec. 31, 2016		$ 5,941,308	$ 468,081	$ 8,198,890	$ (3,089,734)	$ (29,642)	$ 5,547,595	$ 393,713
Balance (in shares) at Dec. 31, 2016			468,081
Increase (Decrease) in Stockholders' Equity
Net income (loss)		422,634			414,169		414,169	8,465
Other comprehensive income (loss)		5,618				5,618	5,618
Issuance of common stock, net		27,353	$ 1,402	25,951			27,353	0
Issuance of common stock, net (in shares)			1,402
Conversion of DownREIT units to common stock		0	$ 78	2,411			2,489	(2,489)
Conversion of DownREIT units to common stock (in shares)			78
Repurchase of common stock		(4,785)	$ (157)	(4,628)			(4,785)
Repurchase of common stock (in shares)			(157)
Exercise of stock options		768	$ 32	736			768
Exercise of stock options (in shares)			32
Amortization of deferred compensation		14,258		14,258			14,258
Common dividends		(694,955)			(694,955)		(694,955)
Distributions to noncontrolling interests		(26,129)		0			0	(26,129)
Issuances of noncontrolling interests		1,615						1,615
Deconsolidation of noncontrolling interests		(58,062)		0	0		0	(58,062)
Purchase of noncontrolling interests		(34,685)		(11,505)			(11,505)	(23,180)
Balance at Dec. 31, 2017		5,594,938	$ 469,436	8,226,113	(3,370,520)	(24,024)	5,301,005	293,933
Balance (in shares) at Dec. 31, 2017			469,436
Increase (Decrease) in Stockholders' Equity
Cumulative effect of new accounting principle	[1]	79,144			79,144		79,144
Adjusted balance, January 1		5,674,082	$ 469,436	8,226,113	(3,291,376)	(24,024)	5,380,149	293,933
Net income (loss)		1,073,474			1,061,093		1,061,093	12,381
Other comprehensive income (loss)		19,316				19,316	19,316
Issuance of common stock, net		215,179	$ 8,078	207,101			215,179
Issuance of common stock, net (in shares)			8,078
Conversion of DownREIT units to common stock		0	$ 3	133			136	(136)
Conversion of DownREIT units to common stock (in shares)			3
Repurchase of common stock		(3,432)	$ (141)	(3,291)			(3,432)
Repurchase of common stock (in shares)			(141)
Exercise of stock options		2,477	$ 120	2,357			2,477
Exercise of stock options (in shares)			120
Amortization of deferred compensation		16,563		16,563			16,563
Common dividends		(696,913)			(696,913)		(696,913)
Distributions to noncontrolling interests		(18,415)		0				(18,415)
Issuances of noncontrolling interests		299,666						299,666
Purchase of noncontrolling interests		(69,406)		(50,129)			(50,129)	(19,277)
Balance at Dec. 31, 2018		6,512,591	$ 477,496	8,398,847	(2,927,196)	(4,708)	5,944,439	568,152
Balance (in shares) at Dec. 31, 2018			477,496
Increase (Decrease) in Stockholders' Equity
Cumulative effect of new accounting principle	[2]	590			590		590
Adjusted balance, January 1		6,513,181	$ 477,496	8,398,847	(2,926,606)	(4,708)	5,945,029	568,152
Net income (loss)		60,061			45,530		45,530	14,531
Other comprehensive income (loss)		1,851				1,851	1,851
Issuance of common stock, net		791,048	$ 27,523	763,525			791,048
Issuance of common stock, net (in shares)			27,523
Conversion of DownREIT units to common stock		0	$ 213	4,932			5,145	$ (5,145)
Conversion of DownREIT units to common stock (in shares)			213					7,000
Repurchase of common stock		(5,043)	$ (162)	(4,881)			(5,043)
Repurchase of common stock (in shares)			(162)
Exercise of stock options		4,538	$ 152	4,386			4,538
Exercise of stock options (in shares)			152
Amortization of deferred compensation		18,162		18,162			18,162
Common dividends		(720,123)			(720,123)		(720,123)
Distributions to noncontrolling interests		(28,301)						$ (28,301)
Issuances of noncontrolling interests		33,318						33,318
Purchase of noncontrolling interests		(1,218)		(1,079)			(1,079)	(139)
Balance at Dec. 31, 2019		$ 6,667,474	$ 505,222	$ 9,183,892	$ (3,601,199)	$ (2,857)	$ 6,085,058	$ 582,416
Balance (in shares) at Dec. 31, 2019			505,222

[1] On January 1, 2018, the Company adopted Accounting Standards Update (“ASU”) No. 2017-05, Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets (“ASU 2017-05”), and recognized the cumulative-effect of adoption to beginning retained earnings. Refer to Note 2 for a detailed impact of adoption.

[2] On January 1, 2019, the Company adopted a series of ASUs related to accounting for leases, and recognized the cumulative-effect of adoption to beginning retained earnings. Refer to Note 2 for a detailed impact of adoption.