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
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
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)		43,237			40,232		40,232	3,005
Other comprehensive income (loss)		2,717				2,717	2,717
Issuance of common stock, net		2,774	$ 382	2,392			2,774
Issuance of common stock, net (in shares)			382
Repurchase of common stock		(2,144)	$ (93)	(2,051)			(2,144)
Repurchase of common stock (in shares)			(93)
Amortization of deferred compensation		5,919		5,919			5,919
Common dividends ($0.37 per share)		(174,149)			(174,149)		(174,149)
Distributions to noncontrolling interests		(5,077)		0				(5,077)
Issuances of noncontrolling interests		995						995
Purchase of noncontrolling interests		(67,431)		(49,207)			(49,207)	(18,224)
Balance at Mar. 31, 2018		5,480,923	$ 469,725	8,183,166	(3,425,293)	(21,307)	5,206,291	274,632
Balance (in shares) at Mar. 31, 2018			469,725
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
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
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)		64,990			61,470		61,470	3,520
Other comprehensive income (loss)		825				825	825
Issuance of common stock, net		1,532	$ 342	1,190			1,532
Issuance of common stock, net (in shares)			342
Conversion of DownREIT units to common stock		0	$ 184	3,890			4,074	(4,074)
Conversion of DownREIT units to common stock (in shares)			184
Repurchase of common stock		(2,919)	$ (95)	(2,824)			(2,919)
Repurchase of common stock (in shares)			(95)
Exercise of stock options (in shares)			2
Exercise of stock options		46	$ 2	44			46
Amortization of deferred compensation		4,111		4,111			4,111
Common dividends ($0.37 per share)		(177,286)			(177,286)		(177,286)
Distributions to noncontrolling interests		(5,415)						(5,415)
Balance at Mar. 31, 2019		$ 6,399,065	$ 477,929	$ 8,405,258	$ (3,042,422)	$ (3,883)	$ 5,836,882	$ 562,183
Balance (in shares) at Mar. 31, 2019			477,929

[1] On January 1, 2018, the Company adopted 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 Accounting Standards Updates (“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.