Debt - Narrative (Details) - USD ($)	1 Months Ended					6 Months Ended	8 Months Ended	12 Months Ended
Debt - Narrative (Details) - USD ($)	Dec. 31, 2025	Nov. 30, 2025	Aug. 31, 2025	Jul. 31, 2025	Jun. 30, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Apr. 30, 2025
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Notional balance	$ 550,000,000					$ 550,000,000	$ 550,000,000	$ 550,000,000
Commercial paper, maximum aggregate amount outstanding	1,000,000,000					1,000,000,000	1,000,000,000	1,000,000,000			$ 500,000,000
Repayment of unsecured debt								825,000,000	$ 300,000,000	$ 750,000,000
Total net real estate	20,806,242,000					20,806,242,000	20,806,242,000	$ 20,806,242,000	19,767,062,000
Percentage of principle amount at which the entity may redeem some or all of the notes								100.00%
Interest Rate Swap, Entered Into 2025 \| Cash Flow Hedges Interest Rate Caps
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Notional balance	550,000,000					550,000,000	550,000,000	$ 550,000,000
Asset Pledged as Collateral \| Notes Payable, Other Payables
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Total net real estate	1,208,731,000					1,208,731,000	$ 1,208,731,000	1,208,731,000
Minimum
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)							(0.02%)
Maximum
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)							0.02%
Variable rate unsecured credit facility
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Available borrowing capacity	$ 2,500,000,000					$ 2,500,000,000	$ 2,500,000,000	$ 2,500,000,000	$ 2,250,000,000		2,250,000,000
Debt instrument, effective interest rate (as a percent)	4.58%					4.58%	4.58%	4.58%
Debt instrument, basis spread on variable rate (as a percent)							0.705%
Line of credit facility, commitment fee (as a percent)							0.12%
Debt instrument, basis spread on variable rate, increase (decrease)	0.02%					0.02%	0.02%	0.02%
Line of credit facility, commitment fee percentage, increase (decrease)						0.005%
Variable rate unsecured credit facility \| Minimum
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)							0.65%
Line of credit facility, commitment fee (as a percent)							0.10%
Variable rate unsecured credit facility \| Maximum
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)							1.40%
Line of credit facility, commitment fee (as a percent)							0.30%
Variable Rate Unsecured Term Loan $550 Million
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, increase (decrease), other, net			$ 100,000,000
Variable Rate Unsecured Term Loan $550 Million \| Minimum
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)							0.70%
Variable Rate Unsecured Term Loan $550 Million \| Maximum
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)							1.60%
Unsecured Notes 4.350 Percent
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Proceeds from issuance of debt	$ 397,424,000
Unsecured notes \| Minimum
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)								10.00%
Unsecured notes \| Maximum
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)								30.00%
Unsecured notes \| Variable Rate Unsecured Term Loan $550 Million
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, effective interest rate (as a percent)	4.44%					4.44%	4.44%	4.44%
Debt instrument, basis spread on variable rate, increase (decrease)	(0.78%)					(0.78%)	(0.78%)	(0.78%)
Face amount, debt instrument	$ 550,000,000					$ 550,000,000	$ 550,000,000	$ 550,000,000			$ 450,000,000
Unsecured notes \| Notes Payable 3.450 Maturities 2025
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Repayment of unsecured debt					$ 525,000,000
Stated interest rate (as a percent)					3.45%
Unsecured notes \| Unsecured Notes, 5.00%
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, effective interest rate (as a percent)				5.05%
Stated interest rate (as a percent)				5.00%
Unsecured notes \| Notes Payable 3.500 Maturities 2025
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Repayment of unsecured debt		$ 300,000,000
Stated interest rate (as a percent)		3.50%
Unsecured notes \| Unsecured Notes 4.350 Percent
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, effective interest rate (as a percent)	4.52%					4.52%	4.52%	4.52%
Stated interest rate (as a percent)	4.35%					4.35%	4.35%	4.35%
Long-Term Debt \| Unsecured Notes, 5.00%
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Face amount, debt instrument				$ 400,000,000
Long-Term Debt \| Unsecured Notes 4.350 Percent
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Face amount, debt instrument	$ 400,000,000					$ 400,000,000	$ 400,000,000	$ 400,000,000
Unsecured Notes, 5.00%
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Proceeds from issuance of debt				$ 394,888,000

AVALONBAY COMMUNITIES INC 10-K