Allowance for Loan Loss (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	$ 4,757	$ 4,643
Financing Receivable, Allowance for Credit Losses, Charge-offs	(58)	(79)
Financing Receivable, Allowance for Credit Losses, Recoveries	33	24
Financing Receivable Allowance For Credit Losses Net Chargeoffs Recoveries	(25)	(55)
Provision for loan losses	0	0
Financing Receivable, Allowance for Credit Losses	4,732	4,588
Commercial and Industrial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	653	540
Financing Receivable, Allowance for Credit Losses, Charge-offs	(52)	0
Financing Receivable, Allowance for Credit Losses, Recoveries	14	2
Financing Receivable Allowance For Credit Losses Net Chargeoffs Recoveries	(38)	2
Provision for loan losses	109	(18)
Financing Receivable, Allowance for Credit Losses	724	524
Construction And Land Development Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	734	812
Financing Receivable, Allowance for Credit Losses, Charge-offs	0	0
Financing Receivable, Allowance for Credit Losses, Recoveries	0	5
Financing Receivable Allowance For Credit Losses Net Chargeoffs Recoveries	0	5
Provision for loan losses	(64)	28
Financing Receivable, Allowance for Credit Losses	670	845
Commercial Real Estate Loans, Total [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	2,126	2,071
Financing Receivable, Allowance for Credit Losses, Charge-offs	0	0
Financing Receivable, Allowance for Credit Losses, Recoveries	0	0
Financing Receivable Allowance For Credit Losses Net Chargeoffs Recoveries	0	0
Provision for loan losses	(7)	(67)
Financing Receivable, Allowance for Credit Losses	2,119	2,004
Residential Real Estate Loans, Total [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	1,071	1,107
Financing Receivable, Allowance for Credit Losses, Charge-offs	(4)	(78)
Financing Receivable, Allowance for Credit Losses, Recoveries	16	14
Financing Receivable Allowance For Credit Losses Net Chargeoffs Recoveries	12	(64)
Provision for loan losses	(30)	21
Financing Receivable, Allowance for Credit Losses	1,053	1,064
Consumer Installment and Revolving Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	173	113
Financing Receivable, Allowance for Credit Losses, Charge-offs	(2)	(1)
Financing Receivable, Allowance for Credit Losses, Recoveries	3	3
Financing Receivable Allowance For Credit Losses Net Chargeoffs Recoveries	1	2
Provision for loan losses	(8)	36
Financing Receivable, Allowance for Credit Losses	$ 166	$ 151

No definition available.

Name:	aubn_FinancingReceivableAllowanceForCreditLossesNetChargeoffsRecoveries
Namespace Prefix:	aubn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of recovery of financing receivables doubtful of collection that were previously charged off.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount of direct write-downs of financing receivables charged against the allowance.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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- Details

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- Details

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- Details

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