Real Estate Disposition Activities (Details) ft² in Thousands, $ in Thousands	3 Months Ended			12 Months Ended
	Sep. 30, 2025 USD ($) home	Jun. 30, 2025 USD ($) home	Mar. 31, 2025 USD ($) home	Dec. 31, 2025 USD ($) ft² home community	Dec. 31, 2024 USD ($) ft² home	Dec. 31, 2023 USD ($) home ft²
Summary of income from discontinued operations
Gain on sale of communities, net				$ 335,713	$ 363,300	$ 287,424
Number of communities held for sale \| community				3
Avalon Wilton on River Road
Summary of income from discontinued operations
Number of apartment homes sold \| home			102
Sale of Real Estate Gross Sales Price			$ 65,100
Gain on sale of communities, net			$ 56,476
Commercial square feet \| ft²				0
Avalon Wesmont Station I & II
Summary of income from discontinued operations
Number of apartment homes sold \| home		406
Sale of Real Estate Gross Sales Price		$ 161,500
Gain on sale of communities, net		$ 99,636
Commercial square feet \| ft²				18
Avalon at Gallery Place
Summary of income from discontinued operations
Number of apartment homes sold \| home	203
Sale of Real Estate Gross Sales Price	$ 87,100
Gain on sale of communities, net	$ 63,026
Commercial square feet \| ft²				9
Avalon First and M
Summary of income from discontinued operations
Number of apartment homes sold \| home	469
Sale of Real Estate Gross Sales Price	$ 181,750
Gain on sale of communities, net	$ 41,499
Commercial square feet \| ft²				4
AVA NoMa
Summary of income from discontinued operations
Number of apartment homes sold \| home	438
Sale of Real Estate Gross Sales Price	$ 142,480
Gain on sale of communities, net	$ 31,051
Commercial square feet \| ft²				7
Avalon Brooklyn Bay
Summary of income from discontinued operations
Number of apartment homes sold \| home	180
Sale of Real Estate Gross Sales Price	$ 74,500
Gain on sale of communities, net	$ (1,668)
Commercial square feet \| ft²				0
Archstone Redmond Lakeview
Summary of income from discontinued operations
Number of apartment homes sold \| home	166
Sale of Real Estate Gross Sales Price	$ 63,250
Gain on sale of communities, net	$ 34,454
Commercial square feet \| ft²				0
AVA H Street
Summary of income from discontinued operations
Number of apartment homes sold \| home	138
Sale of Real Estate Gross Sales Price	$ 36,000
Gain on sale of communities, net	$ 12,175
Commercial square feet \| ft²				0
Other real estate
Summary of income from discontinued operations
Sale of Real Estate Gross Sales Price				$ 0
Gain on sale of communities, net				$ 4,241
Commercial square feet \| ft²				0
Wholly owned properties
Summary of income from discontinued operations
Number of apartment homes sold \| home				2,102	1,532	987
Sale of Real Estate Gross Sales Price				$ 811,680	$ 726,200	$ 446,000
Gain on sale of communities, net				$ 340,890	$ 363,208	$ 287,587
Commercial square feet \| ft²				38	24	27

AVALONBAY COMMUNITIES INC 10-K