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	Total 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)		486,278			480,528		480,528	5,750
Other comprehensive income (loss)		2,353				2,353	2,353
Issuance of common stock, net		13,293	$ 850	12,443			13,293
Issuance of common stock, net (in shares)			850
Conversion of DownREIT units to common stock		0	$ 68	2,003			2,071	(2,071)
Conversion of DownREIT units to common stock (in shares)			68
Repurchase of common stock		(4,361)	$ (141)	(4,220)			(4,361)
Repurchase of common stock (in shares)			(141)
Exercise of stock options (in shares)			21
Exercise of stock options		594	$ 21	573			594
Amortization of deferred compensation		7,092		7,092			7,092
Common dividends		(347,118)			(347,118)		(347,118)
Distributions to noncontrolling interest		(13,087)		0				(13,087)
Issuances of noncontrolling interest		650						650
Deconsolidation of noncontrolling interest		(58,061)		0	0			(58,061)
Balance at Jun. 30, 2017		6,028,941	$ 468,879	8,216,781	(2,956,324)	(27,289)	5,702,047	326,894
Balance (in shares) at Jun. 30, 2017			468,879
Increase (Decrease) in Stockholders' Equity
Cumulative effect of new accounting principle	[1]	79,144			79,144		79,144
Adjusted balance		5,674,082	$ 469,436	8,226,113	(3,291,376)	(24,024)	5,380,149	293,933
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
Net income (loss)		136,165			130,174		130,174	5,991
Other comprehensive income (loss)		19,944				19,944	19,944
Issuance of common stock, net		3,433	$ 511	2,922			3,433
Issuance of common stock, net (in shares)			511
Repurchase of common stock		(2,778)	$ (117)	(2,661)			(2,778)
Repurchase of common stock (in shares)			(117)
Amortization of deferred compensation		10,218		10,218			10,218
Common dividends		(348,439)			(348,439)		(348,439)
Distributions to noncontrolling interest		(9,466)						(9,466)
Issuances of noncontrolling interest		995						995
Purchase of noncontrolling interest		(67,431)		(49,207)			(49,207)	(18,224)
Balance at Jun. 30, 2018		$ 5,416,723	$ 469,830	$ 8,187,385	$ (3,509,641)	$ (4,080)	$ 5,143,494	$ 273,229
Balance (in shares) at Jun. 30, 2018			469,830

[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.