CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 1,004,356	$ 827,706	$ 786,103
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense	758,596	707,331	661,578
Amortization of deferred financing costs	7,462	7,454	7,346
Amortization of debt discount	2,681	1,880	1,591
Loss on extinguishment of debt, net	17,787	9,333	602
Amortization of stock-based compensation	25,505	21,603	25,621
Equity (income) in loss of, and return on, unconsolidated entities and noncontrolling interests, net of eliminations	(108)	8,673	12,278
Real estate casualty loss	1,723	0	0
Abandonment of development pursuits	685	9,262	2,943
Unrealized gain on terminated cash flow hedges	(2,654)	(2,894)	0
Cash flow hedge losses reclassified to earnings	7,887	8,984	6,571
Gain on sale of real estate assets	(627,637)	(346,041)	(172,332)
Gain on for-sale condominiums	(3,110)	(8,213)	0
Increase (decrease) in resident security deposits, prepaid expenses and other assets	5,505	(28,675)	(19,118)
Increase in accrued expenses, other liabilities and accrued interest payable	4,492	3,212	8,621
Net cash provided by operating activities	1,203,170	1,219,615	1,321,804
Cash flows from investing activities:
Development/redevelopment of real estate assets including land acquisitions and deferred development costs	(654,861)	(843,907)	(1,052,011)
Acquisition of real estate assets, including partnership interest	(771,692)	0	(420,517)
Capital expenditures - existing real estate assets	(142,688)	(108,531)	(135,626)
Capital expenditures - non-real estate assets	(10,547)	(28,505)	(5,266)
(Decrease) increase in payables for construction	(29,887)	1,474	(4,848)
Proceeds from sale of real estate, net of selling costs	850,230	619,773	422,041
Proceeds from the sale of for-sale condominiums, net of selling costs	124,532	202,033	0
Mortgage note receivable lending	(1,210)	(258)	(692)
Mortgage note receivable payments	2,435	3,419	2,779
Distributions from unconsolidated entities	63,171	11,157	10,454
Investments in unconsolidated entities	(53,536)	(36,088)	(10,183)
Net cash used in investing activities	(624,053)	(179,433)	(1,193,869)
Cash flows from financing activities:
Issuance of common stock, net	31,874	3,464	409,725
Repurchase of common stock, net	0	(183,876)	0
Dividends paid	(888,344)	(883,212)	(839,646)
Issuance of mortgage notes payable	0	51,000	30,250
Repayments of mortgage notes payable, including prepayment penalties	(109,562)	(126,712)	(227,570)
Issuance of unsecured notes	1,098,643	1,296,581	449,804
Repayment of unsecured notes, including prepayment penalties	(462,147)	(958,680)	0
Payment of deferred financing costs	(8,864)	(11,277)	(10,909)
Receipt (payment) for termination of forward interest rate swaps	4,751	(25,135)	(12,309)
Payment to noncontrolling interest	(55)	(68)	456
Payments related to tax withholding for share-based compensation	(13,463)	(14,917)	(16,101)
Distributions to DownREIT partnership unitholders	(48)	(48)	(46)
Distributions to joint venture and profit-sharing partners	(306)	(384)	(439)
Preferred interest obligation redemption and dividends	(1,340)	(1,000)	(1,400)
Net cash used in financing activities	(348,861)	(854,264)	(218,185)
Net increase (decrease) in cash, cash equivalents and cash in escrow	230,256	185,918	(90,250)
Cash and cash equivalents and restricted cash, beginning of year	313,532	127,614	217,864
Cash and cash equivalents and restricted cash, end of year	543,788	313,532	127,614
Cash paid during the year for interest, net of amount capitalized	203,773	196,848	187,570
Supplemental Cash Flow Information
Cash and cash equivalents	420,251	216,976	39,687
Cash in escrow	123,537	96,556	87,927
Cash, cash equivalents and restricted cash shown in the Consolidated Statements of Cash Flows	$ 543,788	$ 313,532	$ 127,614