Summary of Equity in Income of Unconsolidated Entities (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	$ 5,120,000		$ 762,000		$ 1,441,000
CVP I, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	4,493,000	[1]	4,368,000	[1]	7,330,000	[1]
Avalon Bay Value Added Fund, L P
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	2,204,000	[2],[3]	(1,653,000)	[2],[3]	(4,109,000)	[2],[3]
Avalon Del Rey, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	102,000		1,000		79,000
MVP I, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	(626,000)		(881,000)		(684,000)
Avalon Bay Value Added Fund II, L P
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities	(1,053,000)		(1,073,000)		(48,000)
Aria at Hathorne, LLC
Schedule of Equity Method Investments [Line Items]
Equity in income of unconsolidated entities					$ (1,127,000)

[1] Equity in income from this entity for 2011, 2010, and 2009 includes $2,815, $2,839, and $6,192, respectively, relating to the Company's recognition of its promoted interest.

[2] Equity in income for 2011 includes the Company's proportionate share of the gain on the sale of two Fund I assets of $3,063.

[3] Equity in income for 2009 includes an impairment loss of $2,600 for the Company's proportionate share of the impairment charge on an operating community.