Document and Entity Information Document	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Entity Information [Line Items]
Entity Registrant Name	Arrow Financial Corporation
Entity Central Index Key	0000717538
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		12,330,466
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes