Auburn National Bancorporation - Parent Only, Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets:
Cash and due from banks	$ 12,942	$ 15,673
Premises and equipment, net	13,791	12,602
Other assets	7,219	8,652
Total assets	853,381	831,943
Liabilities:
Accrued expenses and other liabilities	2,941	4,040
Long-term debt	3,217	3,217
Total liabilities	766,475	749,766
Stockholders' equity:
Total stockholders' equity	86,906	82,177	$ 79,949
Total liabilities and stockholders' equity	853,381	831,943
Parent Company [Member]
Assets:
Cash and due from banks	1,170	2,190
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	88,741	83,984
Other assets	1,760	881
Total assets	91,671	87,055
Liabilities:
Accrued expenses and other liabilities	1,548	1,661
Long-term debt	3,217	3,217
Total liabilities	4,765	4,878
Stockholders' equity:
Total stockholders' equity	86,906	82,177
Total liabilities and stockholders' equity	$ 91,671	$ 87,055