XML 91 R68.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Recent Accounting Pronouncements - Impact of ASC (Details) - USD ($) | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | --- | --- | ---
Investment Securities |  |  |  |
Allowance for credit losses on investments | $ 213,000 | $ 0 |  |
Loans |  |  |  |
Allowance for credit losses | 35,843,000 | 31,146,000 | $ 31,572,000 | $ 34,246,000
Allowance for credit losses on loans and investments securities |  | 31,146,000 |  |
Liabilities [Abstract] |  |  |  |
Off balance sheet liability, Allowance for loan losses | 7,400,000 | 3,200,000 |  |
Commercial |  |  |  |
Loans |  |  |  |
Allowance for credit losses | 27,902,000 | 23,431,000 | 22,806,000 | 25,811,000
Commercial | Commercial and industrial |  |  |  |
Loans |  |  |  |
Allowance for credit losses | 9,894,000 | 9,233,000 | 9,218,000 | 10,547,000
Commercial | Real estate construction |  |  |  |
Loans |  |  |  |
Allowance for credit losses | 6,111,000 | 1,437,000 | 810,000 | 690,000
Commercial | Commercial real estate |  |  |  |
Loans |  |  |  |
Allowance for credit losses | 11,897,000 | 12,761,000 | 12,778,000 | 14,574,000
Consumer |  |  |  |
Loans |  |  |  |
Allowance for credit losses | 7,941,000 | 7,715,000 | 8,766,000 | 8,435,000
Consumer | Other revolving and installment |  |  |  |
Loans |  |  |  |
Allowance for credit losses | 212,000 | 540,000 | 512,000 | 789,000
Real estate first mortgage | Consumer | Residential |  |  |  |
Loans |  |  |  |
Allowance for credit losses | 6,578,000 | 5,857,000 | 6,874,000 | 6,174,000
Real estate junior lien | Consumer | Residential |  |  |  |
Loans |  |  |  |
Allowance for credit losses | 1,151,000 | 1,318,000 | $ 1,380,000 | $ 1,472,000
Unfunded commitments |  |  |  |
Liabilities [Abstract] |  |  |  |
Off balance sheet liability, Allowance for loan losses | 7,400,000 | 3,244,000 |  |
Mortgage backed securities - Residential agency |  |  |  |
Investment Securities |  |  |  |
Allowance for credit losses on investments | $ 99,000 |  |  |
Accounting Standards Update 2016-13 | Unfunded commitments |  |  |  |
Liabilities [Abstract] |  |  |  |
Off balance sheet liability, Allowance for loan losses |  | 1,900,000 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13 |  |  |  |
Investment Securities |  |  |  |
Allowance for credit losses on investments |  | 172,000 |  |
Loans |  |  |  |
Allowance for credit losses |  | 35,003,000 |  |
Allowance for credit losses on loans and investments securities |  | 35,175,000 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13 | Commercial |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | 25,142,000 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13 | Commercial | Commercial and industrial |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | 8,526,000 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13 | Commercial | Real estate construction |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | 3,986,000 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13 | Commercial | Commercial real estate |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | 12,630,000 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13 | Consumer |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | 9,861,000 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13 | Consumer | Other revolving and installment |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | 444,000 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13 | Real estate first mortgage | Consumer | Residential |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | 8,126,000 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13 | Real estate junior lien | Consumer | Residential |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | 1,291,000 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13 | Unfunded commitments |  |  |  |
Liabilities [Abstract] |  |  |  |
Off balance sheet liability, Allowance for loan losses |  | 5,159,000 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13 | Obligations of state and political agencies |  |  |  |
Investment Securities |  |  |  |
Allowance for credit losses on investments |  | 110,000 |  |
Cumulative Effect, Period of Adoption, Adjusted Balance | Accounting Standards Update 2016-13 | Mortgage backed securities - Residential agency |  |  |  |
Investment Securities |  |  |  |
Allowance for credit losses on investments |  | 62,000 |  |
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 |  |  |  |
Investment Securities |  |  |  |
Allowance for credit losses on investments |  | 172,000 |  |
Loans |  |  |  |
Allowance for credit losses |  | 3,857,000 |  |
Allowance for credit losses on loans and investments securities |  | 4,029,000 |  |
Liabilities [Abstract] |  |  |  |
Off balance sheet liability, Allowance for loan losses |  | 1,900,000 |  |
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 | Commercial |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | 1,711,000 |  |
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 | Commercial | Commercial and industrial |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | (707,000) |  |
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 | Commercial | Real estate construction |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | 2,549,000 |  |
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 | Commercial | Commercial real estate |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | (131,000) |  |
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 | Consumer |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | 2,146,000 |  |
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 | Consumer | Other revolving and installment |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | (96,000) |  |
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 | Real estate first mortgage | Consumer | Residential |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | 2,269,000 |  |
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 | Real estate junior lien | Consumer | Residential |  |  |  |
Loans |  |  |  |
Allowance for credit losses |  | (27,000) |  |
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 | Unfunded commitments |  |  |  |
Liabilities [Abstract] |  |  |  |
Off balance sheet liability, Allowance for loan losses |  | 1,915,000 |  |
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 | Obligations of state and political agencies |  |  |  |
Investment Securities |  |  |  |
Allowance for credit losses on investments |  | 110,000 |  |
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 | Mortgage backed securities - Residential agency |  |  |  |
Investment Securities |  |  |  |
Allowance for credit losses on investments |  | $ 62,000 |  |

X
- Definition Amount excluding accrued interest, of allowance for credit loss on financing receivables and debt securities held to maturity. + References No definition available. + Details
Name: | alrs_FinancingReceivablesAndDebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | alrs_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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 allowance for credit loss on financing receivable. Excludes net investment in lease. + 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_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_LiabilitiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_NotesReceivableNetAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482454/460-10-45-1 + Details
Name: | us-gaap_OffBalanceSheetCreditLossLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_ClassOfFinancingReceivableTypeOfBorrowerAxis=us-gaap_CommercialBorrowerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=alrs_RealEstateConstructionPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ClassOfFinancingReceivableTypeOfBorrowerAxis=us-gaap_ConsumerBorrowerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=alrs_OtherRevolvingAndInstallmentPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=alrs_RealEstateFirstMortgageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=alrs_RealEstateJuniorLienMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_UnfundedLoanCommitmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201613Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CumulativeEffectPeriodOfAdoptionAxis=srt_CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | srt_CumulativeEffectPeriodOfAdoptionAxis=srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |