XML 62 R52.htm IDEA: XBRL DOCUMENT
v3.22.2.2

Retirement Benefit Plans (Details) | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Sep. 30, 2022 USD ($) | Sep. 30, 2021 USD ($) | Sep. 30, 2022 USD ($) | Sep. 30, 2021 USD ($) | Dec. 31, 2022 USD ($) | Dec. 31, 2021
Net Periodic Benefit Cost [Line Items] |  |  |  |  |  |
Interest credit under cash balance plan |  |  | 0.03 |  |  |
Employer matching contribution, percentage |  |  | 5.00% |  |  |
Benefit obligation from lump sum payment to total benefit obligation ratio | 7.91% |  | 7.91% |  |  |
Estimate effect of settlement to be recognized in net periodic cost | $ 550,000 |  | $ 550,000 |  |  |
Forecast |  |  |  |  |  |
Net Periodic Benefit Cost [Line Items] |  |  |  |  |  |
Service cost and interest cost |  |  |  |  | $ 3,316,118 |
Unamortized net (gain) loss |  |  |  |  | $ 7,000,000 |
Employees' Pension Plan |  |  |  |  |  |
Net Periodic Benefit Cost [Line Items] |  |  |  |  |  |
Assumptions used calculating benefit obligation, interest rate to annuitize cash balance account |  |  |  |  |  | 1.02%
Defined benefit plan, increase in benefit payable, percent | 3.00% |  | 3.00% |  |  |
Defined benefit plan, benefit obligation, increase (decrease) for plan amendment |  |  | $ 351,638 |  |  |
Defined benefit plan, amortization of service cost |  |  | 9 years 8 months 12 days |  |  |
Service Cost | $ 469,000 | $ 484,000 | $ 1,408,000 | $ 1,451,000 |  |
Interest Cost | 360,000 | 340,000 | 1,079,000 | 1,023,000 |  |
Expected Return on Plan Assets | (1,078,000) | (945,000) | (3,235,000) | (2,835,000) |  |
Amortization of Prior Service Cost | 19,000 | 20,000 | 58,000 | 59,000 |  |
Amortization of Net Loss (Gain) | 550,000 | 0 | 550,000 | 0 |  |
Net Periodic (Benefit) Cost | 320,000 | (101,000) | (140,000) | (302,000) |  |
Plan Contributions During the Period | 0 | 0 | 0 | 0 |  |
Estimated Future Contributions in the Current Fiscal Year | 0 |  | $ 0 |  |  |
Select Executive Retirement Plan |  |  |  |  |  |
Net Periodic Benefit Cost [Line Items] |  |  |  |  |  |
Assumptions used calculating benefit obligation, interest rate to annuitize cash balance account |  |  |  |  |  | 2.72%
Defined benefit plan, amortization of service cost |  |  | 12 years 6 months |  |  |
Defined benefit plan, benefit obligation, period increase (decrease) |  |  | $ 122,797 |  |  |
Service Cost | 208,000 | 146,000 | 626,000 | 437,000 |  |
Interest Cost | 57,000 | 48,000 | 169,000 | 143,000 |  |
Expected Return on Plan Assets | 0 | 0 | 0 | 0 |  |
Amortization of Prior Service Cost | 11,000 | 12,000 | 33,000 | 36,000 |  |
Amortization of Net Loss (Gain) | 53,000 | 44,000 | 159,000 | 134,000 |  |
Net Periodic (Benefit) Cost | 329,000 | 250,000 | 987,000 | 750,000 |  |
Plan Contributions During the Period | 116,000 | 118,000 | 347,000 | 354,000 |  |
Estimated Future Contributions in the Current Fiscal Year | 116,000 |  | 116,000 |  |  |
Post-Retirement Benefit Plans |  |  |  |  |  |
Net Periodic Benefit Cost [Line Items] |  |  |  |  |  |
Assumptions used calculating benefit obligation, interest rate to annuitize cash balance account |  |  |  |  |  | 3.08%
Service Cost | 23,000 | 27,000 | 68,000 | 82,000 |  |
Interest Cost | 61,000 | 62,000 | 185,000 | 186,000 |  |
Expected Return on Plan Assets | 0 | 0 | 0 | 0 |  |
Amortization of Prior Service Cost | 27,000 | 27,000 | 80,000 | 80,000 |  |
Amortization of Net Loss (Gain) | (39,000) | (22,000) | (117,000) | (66,000) |  |
Net Periodic (Benefit) Cost | 72,000 | 94,000 | 216,000 | 282,000 |  |
Plan Contributions During the Period | 43,000 | $ 32,000 | 131,000 | $ 87,000 |  |
Estimated Future Contributions in the Current Fiscal Year | $ 43,000 |  | $ 43,000 |  |  |
On or Subsequent to January 1, 2003 |  |  |  |  |  |
Net Periodic Benefit Cost [Line Items] |  |  |  |  |  |
Service credits, percent of eligible salaries |  |  | 6.00% |  |  |
Minimum | Prior to January 1, 2003 |  |  |  |  |  |
Net Periodic Benefit Cost [Line Items] |  |  |  |  |  |
Service credits, percent of eligible salaries |  |  | 6.00% |  |  |
Maximum | Prior to January 1, 2003 |  |  |  |  |  |
Net Periodic Benefit Cost [Line Items] |  |  |  |  |  |
Service credits, percent of eligible salaries |  |  | 12.00% |  |  |

X
- Definition Cash Balance Service Credits Percent Of Eligible Salaries + References No definition available. + Details
Name: | arow_CashBalanceServiceCreditsPercentOfEligibleSalaries
Namespace Prefix: | arow_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan, Amortization Of Service Cost + References No definition available. + Details
Name: | arow_DefinedBenefitPlanAmortizationOfServiceCost
Namespace Prefix: | arow_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Interest Rate to Annuitize Cash Balance Account + References No definition available. + Details
Name: | arow_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationInterestRateToAnnuitizeCashBalanceAccount
Namespace Prefix: | arow_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Benefit Obligation From Lump Sum Payment To Total Benefit Obligation Ratio + References No definition available. + Details
Name: | arow_DefinedBenefitPlanBenefitObligationFromLumpSumPaymentToTotalBenefitObligationRatio
Namespace Prefix: | arow_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Estimated Effect Of Settlement To Be Recognized In Net Periodic Benefit Cost + References No definition available. + Details
Name: | arow_DefinedBenefitPlanEstimatedEffectOfSettlementToBeRecognizedInNetPeriodicBenefitCost
Namespace Prefix: | arow_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Defined Benefit Plan, Increase In Benefit Payable, Percent + References No definition available. + Details
Name: | arow_DefinedBenefitPlanIncreaseInBenefitPayablePercent
Namespace Prefix: | arow_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Service Cost And Interest Cost + References No definition available. + Details
Name: | arow_DefinedBenefitPlanServiceCostAndInterestCost
Namespace Prefix: | arow_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Defined Benefit Plan, Unamortized Net Gain (Loss) + References No definition available. + Details
Name: | arow_DefinedBenefitPlanUnamortizedNetGainLoss
Namespace Prefix: | arow_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Interest Credit Under Cash Balance Plan + References No definition available. + Details
Name: | arow_InterestCreditUnderCashBalancePlan
Namespace Prefix: | arow_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 3A -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123453770&loc=SL108413299-114919 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(4) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 18 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(4) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(5) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 3A -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123453770&loc=SL108413299-114919 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 18 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(5) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) in benefit obligation of defined benefit plan. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanBenefitObligationPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of contribution received by defined benefit plan from employer which increases plan assets. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 18 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanContributionsByEmployer
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 No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of contribution expected to be received by defined benefit plan from employer in next fiscal year following current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (g) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 18 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 18 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(3) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 3A -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123453770&loc=SL108413299-114919 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(3) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of cost recognized for passage of time related to defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(2) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 3A -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123453770&loc=SL108413299-114919 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 18 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(2) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920 + Details
Name: | us-gaap_DefinedBenefitPlanInterestCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of net periodic benefit cost (credit) for defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 18 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) in benefit obligation of defined benefit plan from change in terms of existing plan or initiation of new plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(7) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanPlanAmendments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(1) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 18 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921 + Details
Name: | us-gaap_DefinedBenefitPlanServiceCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage employer matches of the employee's percentage contribution matched. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | arow_ParticipationYearAxis=arow_OnOrSubsequenttoJanuary12003Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | arow_ParticipationYearAxis=arow_PriortoJanuary12003Member
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: |