Parent Only Financial Information Parent Only Income Statement (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Interest and Dividends on Investments	$ 64,138	$ 69,379	$ 76,791
Other Operating Income	1,024	1,170	746
Net Gains on Securities Transactions	540	865	2,795
Interest Expense	7,922	11,957	18,679
Salaries and Employee Benefits	31,182	31,703	30,205
Other Operating Expense	12,656	11,640	11,044
Income Tax Expense (Benefit)	(9,079)	(9,661)	(9,714)
Net Income	21,795	22,179	21,933
Arrow Financial Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Dividends from Bank Subsidiaries	12,900	12,700	14,450
Interest and Dividends on Investments	116	123	127
Other Operating Income	549	776	596
Net Gains on Securities Transactions	0	63	17
Total Income	13,565	13,662	15,190
Interest Expense	640	692	669
Salaries and Employee Benefits	59	75	92
Other Operating Expense	860	957	820
Total Expense	1,559	1,724	1,581
Income Before Income Tax Benefit and Equity in Undistributed Net Income of Subsidiaries	12,006	11,938	13,609
Income Tax Expense (Benefit)	634	575	477
Equity in Undistributed Net Income of Subsidiaries	9,155	9,666	7,847
Net Income	$ 21,795	$ 22,179	$ 21,933