XML 65 R52.htm IDEA: XBRL DOCUMENT
v3.25.3

Investment Securities - Additional information (Details) | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2025 USD ($) position security | Sep. 30, 2024 USD ($) | Sep. 30, 2025 USD ($) position security | Sep. 30, 2024 USD ($) | Dec. 31, 2024 USD ($) | Jun. 30, 2025 USD ($) | Jun. 30, 2024 USD ($) | Dec. 31, 2023 USD ($)
INVESTMENT SECURITIES: |  |  |  |  |  |  |  |
Investment trading account | $ 5,000,000 |  | $ 5,000,000 |  |  |  |  |
Cash held in the account available for future security purchases | 774,000 |  | 774,000 |  |  |  |  |
Gross investment losses |  |  |  | $ 0 |  |  |  |
Gross investment gains |  |  |  | 0 |  |  |  |
Accrued interest receivable on held to maturity debt securities | 427,000 |  | 427,000 |  | $ 403,000 |  |  |
Proceeds from sale of investment securities - available for sale | 0 | $ 0 | 0 | 935,000 |  |  |  |
Book value of securities available for sale and held to maturity | 142,300,000 |  | $ 142,300,000 |  | $ 125,800,000 |  |  |
Premium percentage on mortgage backed securities purchased |  |  | 100.70% |  |  |  |  |
The weighted average duration of the total investment securities portfolio |  |  | 44 months 18 days |  | 50 months 9 days |  |  |
Accrued interest receivable on available for sale debt securities | $ 1,100,000 |  | $ 1,100,000 |  | $ 833,000 |  |  |
Number of available for sale debt securities in non accrual status | security | 0 |  | 0 |  |  |  |  |
Charge-off of a non-performing security totaling | $ 1,000,000 |  | $ 1,000,000 | 491,000 |  |  |  |
Available-for-Sale debt securities in non-accrual |  |  |  |  | 1,000,000 |  |  |
Percentage of unrealized loss position for less than 12 months |  |  | 7.40% |  |  |  |  |
Percentage of unrealized loss position for greater than 12 months |  |  | 10.60% |  |  |  |  |
Available for sale securities, allowance for credit losses | 0 | 360,000 | $ 0 | 360,000 | 360,000 | $ 1,000,000 | $ 360,000 | $ 926,000
Carrying value of equity securities without readily determinable fair values | 600,000 |  | 600,000 |  | 600,000 |  |  |
Investment securities held to maturity, Allowance for credit losses | (94,000) | (88,000) | (94,000) | (88,000) | (89,000) | (85,000) | (100,000) | (37,000)
Held to maturity debt securities in non-accrual | $ 0 |  | $ 0 |  | 0 |  |  |
U.S. Agency |  |  |  |  |  |  |  |
INVESTMENT SECURITIES: |  |  |  |  |  |  |  |
Unrealized loss position for greater than 12 months, Number of positions | position | 6 |  | 6 |  |  |  |  |
Investment securities held to maturity, Allowance for credit losses | $ 0 |  | $ 0 |  |  |  |  |
U.S. Agency mortgage-backed securities |  |  |  |  |  |  |  |
INVESTMENT SECURITIES: |  |  |  |  |  |  |  |
Unrealized loss position for less than 12 months, Number of positions | position | 3 |  | 3 |  |  |  |  |
Unrealized loss position for greater than 12 months, Number of positions | position | 129 |  | 129 |  |  |  |  |
Investment securities held to maturity, Allowance for credit losses | $ 0 |  | $ 0 |  |  |  |  |
Municipal |  |  |  |  |  |  |  |
INVESTMENT SECURITIES: |  |  |  |  |  |  |  |
Unrealized loss position for greater than 12 months, Number of positions | position | 22 |  | 22 |  |  |  |  |
Investment securities held to maturity, Allowance for credit losses | $ (1,000) | (2,000) | $ (1,000) | (2,000) | (2,000) | (2,000) | (2,000) | (2,000)
Corporate bonds |  |  |  |  |  |  |  |
INVESTMENT SECURITIES: |  |  |  |  |  |  |  |
Charge-off of a non-performing security totaling | $ 1,000,000 |  | $ 1,000,000 | 491,000 |  |  |  |
Unrealized loss position for less than 12 months, Number of positions | position | 5 |  | 5 |  |  |  |  |
Unrealized loss position for greater than 12 months, Number of positions | position | 44 |  | 44 |  |  |  |  |
Available for sale securities, allowance for credit losses |  | $ 360,000 |  | $ 360,000 | $ 360,000 | $ 1,000,000 | $ 360,000 | $ 926,000
Revolving credit facility |  |  |  |  |  |  |  |
INVESTMENT SECURITIES: |  |  |  |  |  |  |  |
Collateral amount | $ 3,800,000 |  | $ 3,800,000 |  |  |  |  |
Standard & Poor's, AAA Rating |  |  |  |  |  |  |  |
INVESTMENT SECURITIES |  |  |  |  |  |  |  |
Portfolio rated | 1.00% |  | 1.00% |  | 59.20% |  |  |
Standard & Poor's, AA Rating |  |  |  |  |  |  |  |
INVESTMENT SECURITIES |  |  |  |  |  |  |  |
Portfolio rated | 76.10% |  | 76.10% |  | 72.80% |  |  |
Securities rated below A |  |  |  |  |  |  |  |
INVESTMENT SECURITIES |  |  |  |  |  |  |  |
Portfolio rated | 12.60% |  | 12.60% |  | 14.70% |  |  |
Maximum |  |  |  |  |  |  |  |
INVESTMENT SECURITIES: |  |  |  |  |  |  |  |
The weighted average duration of the total investment securities portfolio |  |  | 60 months |  |  |  |  |

X
- Definition Number of available for sale debt securities in non accrual status. + References No definition available. + Details
Name: | asrv_AvailableForSaleDebtSecurityInNonAccrualStatusNumberOfSecurities
Namespace Prefix: | asrv_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Premium percentage on mortgage backed securities purchased. + References No definition available. + Details
Name: | asrv_DebtAndEquitySecuritiesPurchasedPremiumPercentage
Namespace Prefix: | asrv_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount excluding accrued interest of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) on nonaccrual status. + References No definition available. + Details
Name: | asrv_DebtSecuritiesAvailableForSaleExcludingAccruedInterestNonaccrual
Namespace Prefix: | asrv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Investment securities. + References No definition available. + Details
Name: | asrv_InvestmentSecuritiesAdditionalTextualAbstract
Namespace Prefix: | asrv_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of depreciation on available for sale debt securities with continuous loss position for greater than 12 months. + References No definition available. + Details
Name: | asrv_PercentageOfDepreciationOnAvailableForSaleDebtSecuritiesAmortizedCostBasisUnrealizedLossPositionGreaterThanTwelveMonths
Namespace Prefix: | asrv_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of depreciation on available for sale debt securities with continuous loss position for less than 12 months. + References No definition available. + Details
Name: | asrv_PercentageOfDepreciationOnAvailableForSaleDebtSecuritiesAmortizedCostBasisUnrealizedLossPositionLessThanTwelveMonths
Namespace Prefix: | asrv_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of investment securities portfolio rated. + References No definition available. + Details
Name: | asrv_PercentageOfInvestmentSecuritiesPortfolioRated
Namespace Prefix: | asrv_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of cash held in the account available for future security purchases. + References No definition available. + Details
Name: | asrv_TradingSecuritiesInvestmentInFutureTradingSecurities
Namespace Prefix: | asrv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The weighted average duration of the total investment securities portfolio. + References No definition available. + Details
Name: | asrv_WeightedAverageDurationOfInvestmentSecuritiesPortfolio
Namespace Prefix: | asrv_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of assets pledged to secure a debt instrument. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477734/942-470-50-3 + Details
Name: | us-gaap_DebtInstrumentCollateralAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, after allowance for credit loss, of accrued interest on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2A -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2A Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 3A -Publisher FASB -URI https://asc.fasb.org/1943274/2147479106/326-30-50-3A Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479106/326-30-50-3B + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest, of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without an allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479106/326-30-50-4 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without an allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479106/326-30-50-4 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount, excluding accrued interest, of decrease in allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) from writeoff. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (g) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479106/326-30-50-9 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestAllowanceForCreditLossWriteoff
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-9 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleRealizedGain
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-9 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleRealizedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, before allowance for credit loss, of accrued interest on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B + Details
Name: | us-gaap_DebtSecuritiesHeldToMaturityAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, excluding accrued interest, of allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 + Details
Name: | us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount excluding accrued interest, of investment in debt security measured at amortized cost (held-to-maturity) on nonaccrual status. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 16 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-16 + Details
Name: | us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestNonaccrual
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of securities, mortgage loans, or other financial instruments pledged as collateral for deposits. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 942 -SubTopic 405 -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478353/942-405-50-1 + Details
Name: | us-gaap_DepositLiabilitiesCollateralIssuedFinancialInstruments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in equity security without readily determinable fair value. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 321 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479536/321-10-50-3 + Details
Name: | us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481830/320-10-45-11 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-9 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-12 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-11 + Details
Name: | us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- 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 -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (aa) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (aaa) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amortized cost of investments in debt securities classified as trading. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_TradingSecuritiesDebtAmortizedCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MunicipalBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateBondSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsAAARatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsAARatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingStandardPoorsAxis=asrv_SecuritiesRatedBelowAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |