Regulatory Matters (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Arrow Financial Corporation [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to Risk Weighted Assets) - Actual Amount	$ 212,360	$ 200,480
Total Capital (to Risk Weighted Assets) - Actual Ratio	15.80%	16.30%
Total Capital (to Risk Weighted Assets) - Minimum Amounts For Capital Adequacy Purposes Amount	107,524	98,395
Total Capital (to Risk Weighted Assets) - Minimum Amounts For Capital Adequacy Purposes Ratio	8.00%	8.00%
Total Capital (to Risk Weighted Assets) - Minimum Amounts To Be Well-Capitalized Amount	134,405	122,994
Total Capital (to Risk Weighted Assets) - Minimum Amounts To Be Well-Capitalized Ratio	10.00%	10.00%
Tier I Capital (to Risk Weighted Assets) - Actual Amount	197,906	185,170
Tier I Capital (to Risk Weighted Assets) - Actual Ratio	14.70%	15.00%
Tier I Capital (to Risk Weighted Assets) - Minimum Acounts For Capital Adequacy Purposes Amount	53,852	49,379
Tier I Capital (to Risk Weighted Assets) - Minimum Amounts For Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier I Capital (to Risk Weighted Assets) - Minimum Amounts To Be Well-Capitalized Ratio	80,778	74,068
Tier I Capital (to Risk Weighted Assets) - Minimum Amounts To Be Well-Capitalized Ratio	6.00%	6.00%
Tier I Capital (to Average Assets) - Actual Amount	197,906	185,170
Tier I Capital (to Average Assets) - Actual Ratio	9.20%	9.10%
Tier I Capital (to Average Assets) - Minimum Amounts For Capital Adequacy Purposes Amount	86,046	81,393
Tier I Capital (to Average Assets) - Minimum Amounts For Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier I Capital (to Average Assets) - Minimum Amounts To Be Well-Capitalized Amount	86,046	81,393
Tier I Capital (to Average Assets) - Minimum Amounts To Be Well-Capitalized Ratio	4.00%	4.00%
Glens Falls National [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to Risk Weighted Assets) - Actual Amount	172,720	164,889
Total Capital (to Risk Weighted Assets) - Actual Ratio	15.40%	16.20%
Total Capital (to Risk Weighted Assets) - Minimum Amounts For Capital Adequacy Purposes Amount	89,725	81,427
Total Capital (to Risk Weighted Assets) - Minimum Amounts For Capital Adequacy Purposes Ratio	8.00%	8.00%
Total Capital (to Risk Weighted Assets) - Minimum Amounts To Be Well-Capitalized Amount	112,156	101,783
Total Capital (to Risk Weighted Assets) - Minimum Amounts To Be Well-Capitalized Ratio	10.00%	10.00%
Tier I Capital (to Risk Weighted Assets) - Actual Amount	160,849	152,205
Tier I Capital (to Risk Weighted Assets) - Actual Ratio	14.40%	14.90%
Tier I Capital (to Risk Weighted Assets) - Minimum Acounts For Capital Adequacy Purposes Amount	44,680	40,860
Tier I Capital (to Risk Weighted Assets) - Minimum Amounts For Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier I Capital (to Risk Weighted Assets) - Minimum Amounts To Be Well-Capitalized Ratio	67,020	61,291
Tier I Capital (to Risk Weighted Assets) - Minimum Amounts To Be Well-Capitalized Ratio	6.00%	6.00%
Tier I Capital (to Average Assets) - Actual Amount	160,849	152,205
Tier I Capital (to Average Assets) - Actual Ratio	8.80%	8.80%
Tier I Capital (to Average Assets) - Minimum Amounts For Capital Adequacy Purposes Amount	73,113	69,184
Tier I Capital (to Average Assets) - Minimum Amounts For Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier I Capital (to Average Assets) - Minimum Amounts To Be Well-Capitalized Amount	91,391	86,480
Tier I Capital (to Average Assets) - Minimum Amounts To Be Well-Capitalized Ratio	5.00%	5.00%
Saratoga National [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to Risk Weighted Assets) - Actual Amount	33,396	31,911
Total Capital (to Risk Weighted Assets) - Actual Ratio	14.80%	15.10%
Total Capital (to Risk Weighted Assets) - Minimum Amounts For Capital Adequacy Purposes Amount	18,052	16,906
Total Capital (to Risk Weighted Assets) - Minimum Amounts For Capital Adequacy Purposes Ratio	8.00%	8.00%
Total Capital (to Risk Weighted Assets) - Minimum Amounts To Be Well-Capitalized Amount	22,565	21,133
Total Capital (to Risk Weighted Assets) - Minimum Amounts To Be Well-Capitalized Ratio	10.00%	10.00%
Tier I Capital (to Risk Weighted Assets) - Actual Amount	30,833	29,297
Tier I Capital (to Risk Weighted Assets) - Actual Ratio	13.70%	13.80%
Tier I Capital (to Risk Weighted Assets) - Minimum Acounts For Capital Adequacy Purposes Amount	9,002	8,492
Tier I Capital (to Risk Weighted Assets) - Minimum Amounts For Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier I Capital (to Risk Weighted Assets) - Minimum Amounts To Be Well-Capitalized Ratio	13,504	12,738
Tier I Capital (to Risk Weighted Assets) - Minimum Amounts To Be Well-Capitalized Ratio	6.00%	6.00%
Tier I Capital (to Average Assets) - Actual Amount	30,833	29,297
Tier I Capital (to Average Assets) - Actual Ratio	9.70%	9.40%
Tier I Capital (to Average Assets) - Minimum Amounts For Capital Adequacy Purposes Amount	12,715	12,467
Tier I Capital (to Average Assets) - Minimum Amounts For Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier I Capital (to Average Assets) - Minimum Amounts To Be Well-Capitalized Amount	$ 15,893	$ 15,584
Tier I Capital (to Average Assets) - Minimum Amounts To Be Well-Capitalized Ratio	5.00%	5.00%