CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net income	$ 435,197	$ 380,306
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation expense	259,685	235,480
Amortization of deferred financing costs	3,827	3,379
Amortization of debt premium	(9,436)	(14,815)
Loss (gain) on extinguishment of debt, net	2,461	(7,749)
Amortization of stock-based compensation	8,482	8,255
Equity in loss of, and return on, unconsolidated entities and noncontrolling interests, net of eliminations	7,255	8,432
Casualty and impairment (gain) loss, net	(3,935)	(17,303)
Cash flow hedge losses reclassified to earnings	2,935	2,992
Gain on sale of real estate assets	(135,735)	(91,456)
Increase in cash in operating escrows	(2,221)	(9,357)
Increase in resident security deposits, prepaid expenses and other assets	(9,936)	(3,439)
Decrease in accrued expenses, other liabilities and accrued interest payable	(13,060)	(2,823)
Net cash provided by operating activities	545,519	491,902
Cash flows from investing activities:
Development/redevelopment of real estate assets including land acquisitions and deferred development costs	(587,287)	(865,497)
Acquisition of real estate assets, including partnership interest	(170,022)	0
Capital expenditures - existing real estate assets	(24,696)	(50,584)
Capital expenditures - non-real estate assets	(3,919)	(1,432)
Proceeds from sale of real estate, net of selling costs	116,941	135,841
Insurance proceeds for property damage claims	17,196	44,142
Increase in payables for construction	2,074	7,126
Distributions from unconsolidated real estate entities	58,870	36,858
Investments in unconsolidated real estate entities	(121,648)	(803)
Net cash used in investing activities	(712,491)	(694,349)
Cash flows from financing activities:
Issuance of common stock, net	12,804	97,326
Dividends paid	(356,235)	(318,240)
Repayments of mortgage notes payable, including prepayment penalties	(157,552)	(588,226)
Issuance of unsecured notes	474,838	574,066
Payment of deferred financing costs	(10,014)	(4,277)
Payment for termination of forward interest rate swaps	(14,847)	0
Distributions to DownREIT partnership unitholders	(20)	(19)
Distributions to joint venture and profit-sharing partners	(203)	(187)
Redemption of preferred interest obligation	0	(2,330)
Net cash used in financing activities	(51,229)	(241,887)
Net decrease in cash and cash equivalents	(218,201)	(444,334)
Cash and cash equivalents, beginning of period	400,507	509,460
Cash and cash equivalents, end of period	182,306	65,126
Cash paid during the period for interest, net of amount capitalized	$ 90,355	$ 91,572