FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2024	Dec. 31, 2023
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Derivative Asset Designated as Hedging Instrument, Fair Value	$ 9,425	$ 10,103
Debt instruments - fair value
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	937,311	961,087
Transfers between levels of fair value hierarchy	0
Carrying (Reported) Amount, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Notes receivable	235,382	228,825
Total assets	246,769	246,138
Debt instruments - fair value
Total liabilities	5,786,655	5,823,923
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	937,311	961,087
Carrying (Reported) Amount, Fair Value Disclosure \| Equity Securities \| Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Equity securities	1,962	7,210
Carrying (Reported) Amount, Fair Value Disclosure \| Interest rate contracts \| Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Derivative Asset Designated as Hedging Instrument, Fair Value	9,425	10,103
Estimate of Fair Value, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Notes receivable	225,512	222,755
Total assets	236,899	240,068
Debt instruments - fair value
Total liabilities	5,167,652	5,215,522
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	937,311	961,087
Estimate of Fair Value, Fair Value Disclosure \| Equity Securities \| Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Equity securities	1,962	7,210
Estimate of Fair Value, Fair Value Disclosure \| Interest rate contracts \| Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Derivative Asset Designated as Hedging Instrument, Fair Value	9,425	10,103
Estimate of Fair Value, Fair Value Disclosure \| Level 1 \| Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Total assets	1,962	7,210
Estimate of Fair Value, Fair Value Disclosure \| Level 1 \| Equity Securities \| Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Equity securities	1,962	7,210
Estimate of Fair Value, Fair Value Disclosure \| Level 2 \| Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Total assets	9,425	10,103
Debt instruments - fair value
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	937,311	961,087
Estimate of Fair Value, Fair Value Disclosure \| Level 2 \| Interest rate contracts \| Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Derivative Asset Designated as Hedging Instrument, Fair Value	9,425	10,103
Estimate of Fair Value, Fair Value Disclosure \| Level 3 \| Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Notes receivable	225,512	222,755
Total assets	225,512	222,755
Debt instruments - fair value
Total liabilities	5,167,652	5,215,522
Unsecured Debt \| Carrying (Reported) Amount, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	4,128,501	4,129,010
Unsecured Debt \| Estimate of Fair Value, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	3,603,760	3,611,697
Unsecured Debt \| Estimate of Fair Value, Fair Value Disclosure \| Level 3 \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	3,603,760	3,611,697
Unsecured Debt \| Working capital credit facility \| Carrying (Reported) Amount, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	27,059	4,593
Unsecured Debt \| Working capital credit facility \| Estimate of Fair Value, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	27,059	4,593
Unsecured Debt \| Working capital credit facility \| Estimate of Fair Value, Fair Value Disclosure \| Level 3 \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	27,059	4,593
Unsecured Debt \| Commercial Paper \| Carrying (Reported) Amount, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	390,000	408,075
Unsecured Debt \| Commercial Paper \| Estimate of Fair Value, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	390,000	408,075
Unsecured Debt \| Commercial Paper \| Estimate of Fair Value, Fair Value Disclosure \| Level 3 \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	390,000	408,075
Fixed Rate Debt \| Secured Debt \| Mortgages Notes Payable \| Carrying (Reported) Amount, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	1,214,095	1,215,228
Fixed Rate Debt \| Secured Debt \| Mortgages Notes Payable \| Estimate of Fair Value, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	1,119,833	1,124,140
Fixed Rate Debt \| Secured Debt \| Mortgages Notes Payable \| Estimate of Fair Value, Fair Value Disclosure \| Level 3 \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	1,119,833	1,124,140
Variable Rate Debt \| Secured Debt \| Mortgages Notes Payable \| Carrying (Reported) Amount, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value		40,017
Variable Rate Debt \| Secured Debt \| Mortgages Notes Payable \| Estimate of Fair Value, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value		40,017
Variable Rate Debt \| Secured Debt \| Mortgages Notes Payable \| Estimate of Fair Value, Fair Value Disclosure \| Level 3 \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value		40,017
Variable Rate Debt \| Secured Debt \| Tax-exempt secured notes payable \| Carrying (Reported) Amount, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	27,000	27,000
Variable Rate Debt \| Secured Debt \| Tax-exempt secured notes payable \| Estimate of Fair Value, Fair Value Disclosure \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	27,000	27,000
Variable Rate Debt \| Secured Debt \| Tax-exempt secured notes payable \| Estimate of Fair Value, Fair Value Disclosure \| Level 3 \| Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	$ 27,000	$ 27,000

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