The maximum loan amount that can be authorized under the Paycheck Protection Program.

No definition available.

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

- Definition

Represents the amount of excess loan application received.

+ References

No definition available.

+ Details

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

- Definition

Represents the interest rate on loans receivable.

+ References

No definition available.

+ Details

Name:	asrv_LoansReceivableInterestRate
Namespace Prefix:	asrv_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the term on loans receivable.

+ References

No definition available.

+ Details

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

- Definition

Represents the number of applications received.

+ References

No definition available.

+ Details

Name:	asrv_LoansReceivableNumberOfApplicationsReceived
Namespace Prefix:	asrv_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of guarantee by SBA.

+ References

No definition available.

+ Details

Name:	asrv_LoansReceivablePercentageOfGuaranteeBySba
Namespace Prefix:	asrv_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of loan proceeds used for payroll expenses.

+ References

No definition available.

+ Details

Name:	asrv_LoansReceivablePercentageOfLoanProceedsUsedForPayrollExpenses
Namespace Prefix:	asrv_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of times of average monthly payroll costs.

+ References

No definition available.

+ Details

Name:	asrv_NumberOfTimesOfAverageMonthlyPayrollCosts
Namespace Prefix:	asrv_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Real estate-construction loans, percentage.

+ References

No definition available.

+ Details

Name:	asrv_RealEstateConstructionLoansPercentage
Namespace Prefix:	asrv_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of unrecognized fee income from the PPP loan originations.

+ References

No definition available.

+ Details

Name:	asrv_UnrecognizedFeeIncomeFromPppLoanOriginations
Namespace Prefix:	asrv_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

No definition available.

+ Details

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

- Definition

The aggregate interest and fee income generated by: (1) loans the Entity has positive intent and ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (a) industrial and agricultural; (b) real estate; and (c) real estate construction loans; (d) trade financing; (e) lease financing; (f) home equity lines-of-credit; (g) automobile and other vehicle loans; and (h) credit card and other revolving-type loans and (2) loans and leases held-for-sale which may include mortgage loans, direct financing, and sales-type leases.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.1)
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

+ Details

Name:	us-gaap_InterestAndFeeIncomeLoansAndLeases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)(4)
-URI http://asc.fasb.org/extlink&oid=121568338&loc=d3e45377-112738

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5074-111524

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84159169&loc=d3e10152-111534

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=asrv_PaycheckProtectionProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=asrv_ScenarioOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=asrv_ScenarioTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Loans - Additional information (Details)		3 Months Ended		6 Months Ended
Loans - Additional information (Details)	Mar. 27, 2020 USD ($) item	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
LOANS
Real estate-construction loans, percentage		5.60%		5.60%		4.90%
Loan balances net of unearned income		$ 1,569,000		$ 1,569,000		$ 384,000
Unrecognized fee income from the PPP loan originations		1,184,000		1,184,000
Fee Income from Loans		10,448,000	$ 10,994,000	$ 20,780,000	$ 21,412,000
Paycheck Protection Program (PPP)
LOANS
Number of times of average monthly payroll costs \| item	2.5
Loan amount	$ 10,000,000
Interest rate	1.00%
Percentage of guarantee by SBA	100.00%
Percentage of loan proceeds used for payroll expenses	60.00%
Loans Receivable, Number Of Applications Received				437
Loans Receivable, Excess Of Loan Application Received		$ 66,900,000		$ 66,900,000
Fee Income from Loans				$ 1,000,000
Paycheck Protection Program (PPP) \| originated prior to June 5, 2020
LOANS
Loan term	2 years
Paycheck Protection Program (PPP) \| originated after June 5, 2020
LOANS
Loan term	5 years