Regulatory Matters Other Regulation Disclosures (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Banking and Thrift [Abstract]
Maximum Subsidiary Dividend	$ 27,323

Number represents the maximum amount that could have been paid by subsidiary banks to Arrow (parent company) without prior regulatory approval.

No definition available.

Name:	arow_MaximumSubsidiaryDividend
Namespace Prefix:	arow_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant