CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Real estate:
Land	$ 1,348,767	$ 1,331,775
Buildings and improvements	6,761,517	6,613,865
Furniture, fixtures and equipment	220,753	203,299
Total Capitalized Cost	8,331,037	8,148,939
Less accumulated depreciation	(1,787,021)	(1,705,410)
Net operating real estate	6,544,016	6,443,529
Construction in progress, including land	399,313	309,704
Land held for development	225,896	184,150
Operating real estate assets held for sale, net	18,207	18,262
Total real estate, net	7,187,432	6,955,645
Cash and cash equivalents	290,104	306,426
Cash in escrow	70,130	173,343
Resident security deposits	24,326	22,289
Investments in unconsolidated real estate entities	118,627	121,537
Deferred financing costs, net	31,308	33,284
Deferred development costs	79,186	77,253
Prepaid expenses and other assets	141,629	131,711
Total assets	7,942,742	7,821,488
LIABILITIES AND STOCKHOLDERS' EQUITY
Unsecured notes, net	1,819,478	1,820,141
Variable rate unsecured credit facility
Mortgage notes payable	2,166,679	2,247,516
Dividends payable	79,157	76,676
Payables for construction	33,821	34,433
Accrued expenses and other liabilities	282,880	246,591
Accrued interest payable	37,423	32,248
Resident security deposits	37,289	34,030
Total liabilities	4,456,727	4,491,635
Redeemable noncontrolling interests	6,852	14,262
Stockholders' equity:
Preferred stock, $0.01 par value; $25 liquidation preference; 50,000,000 shares authorized at both June 30, 2011 and December 31, 2010; zero shares issued and outstanding at June 30, 2011 and December 31, 2010, respectively
Common stock, $0.01 par value; 140,000,000 shares authorized at both June 30, 2011 and December 31, 2010; 88,678,968 and 85,899,080 shares issued and outstanding at June 30, 2011 and December 31, 2010, respectively	887	859
Additional paid-in capital	3,863,220	3,593,677
Accumulated earnings less dividends	(368,412)	(282,743)
Accumulated other comprehensive loss	(20,595)	(1,175)
Total stockholders' equity	3,475,100	3,310,618
Noncontrolling interest	4,063	4,973
Total equity	3,479,163	3,315,591
Total liabilities and stockholders' equity	$ 7,942,742	$ 7,821,488