Document And Entity Information (USD $)	9 Months Ended
	Sep. 30, 2011	Oct. 30, 2011	Jun. 30, 2010
Entity Registrant Name	AVATAR HOLDINGS INC
Entity Central Index Key	0000039677
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 170,329,083
Entity Common Stock, Shares Outstanding		12,975,397
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	true
Amendment Description	The purpose of this amendment to our Quarterly Report on Form 10−Q for the quarter ended September 30, 2011, filed with the Securities Exchange Commission on November 14, 2011 (the “Original Form 10−Q”), is to correct immaterial and typographical errors contained in our Consolidated Financial Statements, and the notes thereto, Management’s Discussion and Analysis of Financial Condition and Results of Operations, and in Exhibits 101 – Interactive Data Files. These corrections do not impact our revenue, results of operations, total assets, or total stockholders' equity previously reported in the Original Form 10-Q. No other changes have been made to the Original Form 10−Q. This amendment speaks as of the filing date of the Original Form 10−Q, does not reflect events that may have occurred subsequent to the original filing date and does not otherwise modify or update in any way disclosures made in the Original Form 10−Q.
Document Period End Date	Sep. 30, 2011