CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income	$ 741,733	$ 697,327	$ 352,771
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation expense	477,923	442,682	560,215
Depreciation expense from discontinued operations	0	0	13,500
Amortization of deferred financing costs	6,871	6,383	6,803
Amortization of debt premium	(24,261)	(34,961)	(29,750)
(Gain) loss on extinguishment of debt, net	(26,736)	412	14,921
Amortization of stock-based compensation	15,321	13,927	15,160
Equity in loss of, and return on, unconsolidated entities and noncontrolling interests, net of eliminations	12,225	4,906	33,125
Casualty (gain) loss and impairment loss, net	(17,303)	0	0
Cash flow hedge losses reclassified to earnings	5,774	6,237	59,376
Abandonment of development pursuits	0	1,455	0
Gain on sale of real estate assets	(158,852)	(255,300)	(278,471)
(Increase) decrease in cash in operating escrows	(11,837)	55	(28,960)
Decrease (increase) in resident security deposits, prepaid expenses and other assets	12,783	(3,441)	(5,372)
Increase in accrued expenses, other liabilities and accrued interest payable	23,113	6,959	10,997
Net cash provided by operating activities	1,056,754	886,641	724,315
Cash flows from investing activities:
Development/redevelopment of real estate assets including land acquisitions and deferred development costs	(1,569,326)	(1,241,832)	(1,285,715)
Acquisition of real estate assets, including partnership interest	0	(47,000)	(839,469)
Capital expenditures - existing real estate assets	(48,170)	(46,902)	(24,415)
Capital expenditures - non-real estate assets	(7,695)	(5,923)	(2,200)
Proceeds from sale of real estate, net of selling costs	282,163	297,466	919,682
Insurance recoveries for property damage claims	44,142	0	0
Mortgage note receivable payment	0	21,748	0
(Decrease) increase in payables for construction	(3,230)	7,400	34,779
Distributions from unconsolidated real estate entities	109,181	203,945	42,955
Investments in unconsolidated real estate entities	(6,582)	(5,662)	(26,791)
Net cash used in investing activities	(1,199,517)	(816,760)	(1,181,174)
Cash flows from financing activities:
Issuance of common stock, net	690,184	346,134	4,703
Dividends paid	(655,248)	(593,643)	(526,050)
Issuance of mortgage notes payable	0	53,000	84,928
Repayments of mortgage notes payable, including prepayment penalties	(850,963)	(32,859)	(2,110,347)
Settlement of interest rate contract	0	0	(51,000)
Issuance of unsecured notes	873,088	550,000	750,000
Repayment of unsecured notes	0	(150,000)	(100,000)
Payment of deferred financing costs	(7,343)	(7,820)	(10,100)
Redemption of units for cash by minority partners	(1,088)	0	(1,965)
Distributions to DownREIT partnership unitholders	(38)	(26)	(32)
Distributions to joint venture and profit-sharing partners	(372)	(262)	(317)
Redemption of preferred interest obligation	(14,410)	(6,300)	(35,224)
Net cash provided by (used in) financing activities	33,810	158,224	(1,995,404)
Net (decrease) increase in cash and cash equivalents	(108,953)	228,105	(2,452,263)
Cash and cash equivalents, beginning of year	509,460	281,355	2,733,618
Cash and cash equivalents, end of year	400,507	509,460	281,355
Cash paid during the year for interest, net of amount capitalized	$ 188,782	$ 191,966	$ 179,325