Equity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013
Changes in equity
Balance		$ 6,840,793
Net income attributable to common stockholders		111,648
Cash flow hedge loss reclassified to earnings	1,574	2,965
Change in redemption value of redeemable noncontrolling interest		(329)
Noncontrolling interests income allocation		19
Dividends declared to common stockholders		(276,894)
Issuance of common stock, net of withholdings		1,871,534
Amortization of deferred compensation		14,027
Balance	8,563,763	8,563,763
Common stock
Changes in equity
Balance		1,144
Issuance of common stock, net of withholdings		150
Balance	1,294	1,294
Additional paid-in capital
Changes in equity
Balance		7,086,407
Issuance of common stock, net of withholdings		1,872,418
Amortization of deferred compensation		14,027
Balance	8,972,852	8,972,852
Accumulated earnings less dividends
Changes in equity
Balance		(142,329)
Net income attributable to common stockholders		111,648
Change in redemption value of redeemable noncontrolling interest		(329)
Dividends declared to common stockholders		(276,894)
Issuance of common stock, net of withholdings		(1,034)
Balance	(308,938)	(308,938)
Accumulated other comprehensive loss
Changes in equity
Balance		(108,007)
Cash flow hedge loss reclassified to earnings		2,965
Balance	(105,042)	(105,042)
Total AvalonBay stockholders' equity
Changes in equity
Balance		6,837,215
Net income attributable to common stockholders		111,648
Cash flow hedge loss reclassified to earnings		2,965
Change in redemption value of redeemable noncontrolling interest		(329)
Dividends declared to common stockholders		(276,894)
Issuance of common stock, net of withholdings		1,871,534
Amortization of deferred compensation		14,027
Balance	8,560,166	8,560,166
Noncontrolling interests
Changes in equity
Balance		3,578
Noncontrolling interests income allocation		19
Balance	$ 3,597	$ 3,597