Regulatory Matters (Details) $ in Thousands	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Maximum subsidiary dividend	$ 27,700
Arrow
Actual, Amount
Total Capital (to Risk Weighted Assets)	469,675	$ 452,506
Tier I Capital (to Risk Weighted Assets)	434,101	417,338
Tier One Capital (to Average Assets)	434,101	417,338
Common Equity Tier 1 Capital (to Risk Weighted Assets)	$ 414,050	$ 397,285
Actual, Ratio
Total Capital (to Risk Weighted Assets)	0.148	0.145
Tier I Capital (to Risk Weighted Assets)	0.136	0.134
Tier One Leverage Capital (to Average Assets)	0.097	0.096
Common Equity Tier 1 Capital (to Risk Weighted Assets)	0.130	0.127
Minimum Amounts For Capital Adequacy, Amount
Total Capital (to Risk Weighted Assets)	$ 334,135	$ 328,268
Tier I Capital (to Risk Weighted Assets)	270,490	265,741
Tier One Leverage Capital (to Average Assets)	179,450	173,952
Common Equity Tier 1 Capital (to Risk Weighted Assets)	$ 222,757	$ 218,845
Minimum Amounts For Capital Adequacy Purposes, Ratio
Total Capital (to Risk Weighted Assets)	0.105	0.105
Tier I Capital (to Risk Weighted Assets)	0.085	0.085
Tier One Leverage Capital (to Average Assets)	0.040	0.040
Common Equity Tier 1 Capital (to Risk Weighted Assets)	0.070	0.070
Minimum Amounts To Be Well-Capitalized, Amount
Total Capital (to Risk Weighted Assets)	$ 318,224	$ 312,636
Tier I Capital (to Risk Weighted Assets)	254,579	250,109
Tier One Leverage Capital (to Average Assets)	224,313	217,440
Common Equity Tier 1 Leverage Capital (to Risk Weighted Assets)	$ 206,846	$ 203,214
Minimum Amounts To Be Well-Capitalized
Total Capital (to Risk Weighted Assets)	0.100	0.100
Tier One Risk Based Capital (to Risk Weighted Assets)	0.080	0.080
Tier One Leverage Capital (to Average Assets)	0.050	0.050
Common Equity Tier 1 Capital (to Risk Weighted Assets)	0.065	0.065
Arrow Bank National Association
Actual, Amount
Total Capital (to Risk Weighted Assets)	$ 449,958	$ 435,628
Tier I Capital (to Risk Weighted Assets)	414,384	400,460
Tier One Capital (to Average Assets)	414,384	400,460
Common Equity Tier 1 Capital (to Risk Weighted Assets)	$ 414,333	$ 400,407
Actual, Ratio
Total Capital (to Risk Weighted Assets)	0.143	0.140
Tier I Capital (to Risk Weighted Assets)	0.131	0.129
Tier One Leverage Capital (to Average Assets)	0.093	0.092
Common Equity Tier 1 Capital (to Risk Weighted Assets)	0.131	0.129
Minimum Amounts For Capital Adequacy, Amount
Total Capital (to Risk Weighted Assets)	$ 331,045	$ 327,050
Tier I Capital (to Risk Weighted Assets)	267,989	264,755
Tier One Leverage Capital (to Average Assets)	178,922	173,656
Common Equity Tier 1 Capital (to Risk Weighted Assets)	$ 220,697	$ 218,033
Minimum Amounts For Capital Adequacy Purposes, Ratio
Total Capital (to Risk Weighted Assets)	0.105	0.105
Tier I Capital (to Risk Weighted Assets)	0.085	0.085
Tier One Leverage Capital (to Average Assets)	0.040	0.040
Common Equity Tier 1 Capital (to Risk Weighted Assets)	0.070	0.070
Minimum Amounts To Be Well-Capitalized, Amount
Total Capital (to Risk Weighted Assets)	$ 315,281	$ 311,476
Tier I Capital (to Risk Weighted Assets)	252,225	249,181
Tier One Leverage Capital (to Average Assets)	223,652	217,070
Common Equity Tier 1 Leverage Capital (to Risk Weighted Assets)	$ 204,933	$ 202,459
Minimum Amounts To Be Well-Capitalized
Total Capital (to Risk Weighted Assets)	0.100	0.100
Tier One Risk Based Capital (to Risk Weighted Assets)	0.080	0.080
Tier One Leverage Capital (to Average Assets)	0.050	0.050
Common Equity Tier 1 Capital (to Risk Weighted Assets)	0.065	0.065