Auburn National Bancorporation - Parent Only, Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net earnings	$ 7,454	$ 9,741
Adjustments to reconcile net earnings to net cash provided by operating activties:
Depreciation and amortization	1,666	1,157
Net increase in other assets	(2,656)	(872)
Net increase in accrued expenses and other liabilities	2,399	1,807
Net cash provided by operating activities	9,728	10,850
Cash flows from investing activities:
Net cash used in investing activities	(102,921)	24,085
Cash flows from financing activities:
Stock repurchases	0	(2,721)
Dividends paid	(3,638)	(3,575)
Net cash provided by (used in) financing activities	113,325	(7,568)
Net change in cash and cash equivalents	20,132	27,367
Cash and cash equivalents at beginning of period	92,443	65,076
Cash and cash equivalents at end of period	112,575	92,443
Parent Company [Member]
Cash flows from operating activities:
Net earnings	7,454	9,741
Adjustments to reconcile net earnings to net cash provided by operating activties:
Net increase in other assets	(6)	7
Net increase in accrued expenses and other liabilities	(561)	(215)
Equity In Distributed (Undistributed) Earnings Of Bank Subsidary	3,319	1,059
Net cash provided by operating activities	3,568	8,474
Cash flows from financing activities:
Stock repurchases	0	(2,721)
Dividends paid	(3,638)	(3,575)
Net cash provided by (used in) financing activities	(3,638)	(6,296)
Net change in cash and cash equivalents	(70)	2,178
Cash and cash equivalents at beginning of period	4,119	1,941
Cash and cash equivalents at end of period	$ 4,049	$ 4,119