DOCUMENT AND ENTITY INFORMATION	9 Months Ended
Sep. 30, 2011	Nov. 09, 2011
Entity Registrant Name	RIDGEFIELD ACQUISITION CORP
Entity Central Index Key	0000812152
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Trading Symbol	rdga
Entity Common Stock, Shares Outstanding		1,260,773
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2011
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2011

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