Regulatory Capital Textuals (Details) $ in Millions	Dec. 31, 2020 USD ($)
Regulatory Capital Requirements [Abstract]
Regulatory Capital, Dividends Without Approval Of Regulators	$ 6.8
Regulatory Capital, Restricted Investment From Dividends	$ 96.9

Amount of the parent company's investment in bank that is restricted from transfer as dividends due to regulations on capital

No definition available.

Name:	aubn_RegulatoryCapitalRestrictedInvestmentFromDividends
Namespace Prefix:	aubn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant