The amount of financing receivable excluding accrued interest relating unfunded loan.

No definition available.

Name:	asrv_FinancingReceivableExcludingAccruedInterestUnfundedLoan
Namespace Prefix:	asrv_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of interest income deferred until maturity of financing receivable modified for debtor experiencing financial difficulty.

+ References

No definition available.

+ Details

Name:	asrv_FinancingReceivableModificationsInterestDeferredUntilMaturity
Namespace Prefix:	asrv_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Period for which interest only payment at a reduced rate, of financing receivable modified for debtor experiencing financial difficulty.

+ References

No definition available.

+ Details

Name:	asrv_FinancingReceivableModifiedReducedInterestOnlyPaymentAtReducedRateTerm
Namespace Prefix:	asrv_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph c
-Publisher SEC

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Accumulated amortized cost excluding accrued interest, of financing receivable modified for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestModifiedAccumulated
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, of financing receivable with payment default in current period and modified within previous 12 months preceding payment default for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 44
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-44

+ Details

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

- Definition

Percentage, excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty to total financing receivables.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

Name:	us-gaap_FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of payment deferral of financing receivable modified for debtor experiencing financial difficulty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

Name:	us-gaap_FinancingReceivableModifiedPaymentDeferralPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Period of increase in weighted average maturity of financing receivable modified for debtor experiencing financial difficulty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_FinancingReceivableModifiedWeightedAverageTermIncreaseFromModification
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityAndInterestRateReductionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=asrv_CommercialLoansSecuredByOwnerOccupiedRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_PaymentDeferralMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=asrv_OtherCommercialAndIndustrialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=asrv_CommercialLoansSecuredByNonOwnerOccupiedOtherCommercialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Allowance for Credit Losses - Loans - Loan modifications to borrowers experiencing financial difficulty (Details) - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Financing Receivable, Allowance for Credit Loss [Line Items]
Unfunded loan commitments	$ 0			$ 0			$ 0	$ 0
Modified to borrowers which subsequently defaulted				0				0
Extended Maturity [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis	158,000			417,000			158,000	417,000
Extended Maturity and Interest Rate Reduction [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis	154,000			7,047,000			154,000	7,047,000
Commercial real estate (owner occupied) \| Extended Maturity [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis	$ 158,000						$ 158,000
Percentage of Total Class of Loans	0.20%						0.20%
Commercial real estate (owner occupied) \| Payment Deferral \| Commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Additional amortization period	60 months						60 months
Other commercial and industrial
Financing Receivable, Allowance for Credit Loss [Line Items]
Term extension date	90 days	90 days	90 days		1 year	5 months
Other commercial and industrial \| Extended Maturity [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis				417,000				$ 417,000
Percentage of Total Class of Loans								0.29%
Other commercial and industrial \| Extended Maturity and Interest Rate Reduction [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis	$ 154,000						$ 154,000
Percentage of Total Class of Loans	0.11%						0.11%
Other commercial real estate (non-owner occupied)
Financing Receivable, Allowance for Credit Loss [Line Items]
Term extension date					3 months
Deferred interest income, period					7 months
Deferred interest income					$ 303,000
Other commercial real estate (non-owner occupied) \| Extended Maturity [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Percentage of Total Class of Loans								3.07%
Other commercial real estate (non-owner occupied) \| Extended Maturity and Interest Rate Reduction [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis				$ 7,047,000				$ 7,047,000