Reportable Segments (Tables)

9 Months Ended

Sep. 30, 2012

Reportable Segments (Tables) [Abstracts]

Reportable Segments Schedule

	Quarter Ended September 30, 2012
	Northeast		Northwest		Southeast		Southwest		Other (3)			Total
Rental income:
Same store (1)	$	190,140	$	103,926	$	93,609	$	120,388	$	—		$	508,063
Non-same store/other (2) (3)	21,399		12,226		1,400		10,126		(122		)	45,029
Total rental income	211,539		116,152		95,009		130,514		(122		)	553,092
Operating expenses:
Same store (1)	66,289		34,805		36,949		39,420		—			177,463
Non-same store/other (2) (3)	7,318		5,686		788		3,580		(1,428		)	15,944
Total operating expenses	73,607		40,491		37,737		43,000		(1,428		)	193,407
NOI:
Same store (1)	123,851		69,121		56,660		80,968		—			330,600
Non-same store/other (2) (3)	14,081		6,540		612		6,546		1,306			29,085
Total NOI	$	137,932	$	75,661	$	57,272	$	87,514	$	1,306		$	359,685

(1) Same store primarily includes all properties acquired or completed and stabilized prior to July 1, 2011, less properties subsequently sold, which represented 105,902 apartment units.

(2) Non-same store primarily includes properties acquired after July 1, 2011, plus any properties in lease-up and not stabilized as of July 1, 2011.

(3) Other includes development and other corporate operations.

	Quarter Ended September 30, 2011
	Northeast		Northwest			Southeast		Southwest		Other (3)			Total
Rental income:
Same store (1)	$	180,074	$	95,679		$	89,056	$	115,447	$	—		$	480,256
Non-same store/other (2) (3)	6,034		86			468		3,791		309			10,688
Total rental income	186,108		95,765			89,524		119,238		309			490,944
Operating expenses:
Same store (1)	64,479		33,844			34,437		39,622		—			172,382
Non-same store/other (2) (3)	1,926		195			154		1,673		1,666			5,614
Total operating expenses	66,405		34,039			34,591		41,295		1,666			177,996
NOI:
Same store (1)	115,595		61,835			54,619		75,825		—			307,874
Non-same store/other (2) (3)	4,108		(109		)	314		2,118		(1,357		)	5,074
Total NOI	$	119,703	$	61,726		$	54,933	$	77,943	$	(1,357	)	$	312,948

(1) Same store primarily includes all properties acquired or completed and stabilized prior to July 1, 2011, less properties subsequently sold, which represented 105,902 apartment units.

(2) Non-same store primarily includes properties acquired after July 1, 2011, plus any properties in lease-up and not stabilized as of July 1, 2011.

	Nine Months Ended September 30, 2012
	Northeast		Northwest		Southeast		Southwest		Other (3)			Total
Rental income:
Same store (1)	$	530,972	$	295,518	$	264,709	$	337,232	$	—		$	1,428,431
Non-same store/other (2) (3)	76,922		37,945		14,667		44,834		(164		)	174,204
Total rental income	607,894		333,463		279,376		382,066		(164		)	1,602,635
Operating expenses:
Same store (1)	190,952		100,384		103,333		110,847		—			505,516
Non-same store/other (2) (3)	23,636		18,197		5,793		15,326		1,594			64,546
Total operating expenses	214,588		118,581		109,126		126,173		1,594			570,062
NOI:
Same store (1)	340,020		195,134		161,376		226,385		—			922,915
Non-same store/other (2) (3)	53,286		19,748		8,874		29,508		(1,758		)	109,658
Total NOI	$	393,306	$	214,882	$	170,250	$	255,893	$	(1,758	)	$	1,032,573
Total assets	$	6,945,739	$	3,029,831	$	2,358,093	$	3,286,507	$	1,048,375		$	16,668,545
Capital expenditures	$	42,259	$	27,337	$	22,280	$	21,732	$	927		$	114,535

(1) Same store primarily includes all properties acquired or completed and stabilized prior to January 1, 2011, less properties subsequently sold, which represented 102,241 apartment units.

(2) Non-same store primarily includes properties acquired after January 1, 2011, plus any properties in lease-up and not stabilized as of January 1, 2011.

(3) Other includes development and other corporate operations.

	Nine Months Ended September 30, 2011
	Northeast		Northwest		Southeast		Southwest		Other (3)			Total
Rental income:
Same store (1)	$	502,724	$	272,851	$	253,202	$	324,913	$	—		$	1,353,690
Non-same store/other (2) (3)	33,937		4,217		9,764		18,902		(3,374		)	63,446
Total rental income	536,661		277,068		262,966		343,815		(3,374		)	1,417,136
Operating expenses:
Same store (1)	185,770		97,617		100,102		111,020		—			494,509
Non-same store/other (2) (3)	11,799		1,680		3,528		8,005		5,462			30,474
Total operating expenses	197,569		99,297		103,630		119,025		5,462			524,983
NOI:
Same store (1)	316,954		175,234		153,100		213,893		—			859,181
Non-same store/other (2) (3)	22,138		2,537		6,236		10,897		(8,836		)	32,972
Total NOI	$	339,092	$	177,771	$	159,336	$	224,790	$	(8,836	)	$	892,153

(1) Same store primarily includes all properties acquired or completed and stabilized prior to January 1, 2011, less properties subsequently sold, which represented 102,241 apartment units.

(2) Non-same store primarily includes properties acquired after January 1, 2011, plus any properties in lease-up and not stabilized as of January 1, 2011.

(3) Other includes development, condominium conversion overhead of $0.3 million and other corporate operations.

Reconciliation of NOI

	Nine Months Ended September 30,						Quarter Ended September 30,
	2012			2011			2012			2011
Rental income	$	1,602,635		$	1,417,136		$	553,092		$	490,944
Property and maintenance expense	(325,071		)	(300,362		)	(110,679		)	(101,712		)
Real estate taxes and insurance expense	(182,222		)	(162,430		)	(64,235		)	(57,109		)
Property management expense	(62,769		)	(62,191		)	(18,493		)	(19,175		)
Total operating expenses	(570,062		)	(524,983		)	(193,407		)	(177,996		)
Net operating income	$	1,032,573		$	892,153		$	359,685		$	312,948