XML 42 R40.htm IDEA: XBRL DOCUMENT v2.4.1.9
Loans (Loans Individually Evaluated for Impairment by Class of Loans) (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
With An Allowance Recorded:      
Allowance for Loan Losses Allocated $ 1,579us-gaap_ImpairedFinancingReceivableRelatedAllowance   $ 1,542us-gaap_ImpairedFinancingReceivableRelatedAllowance
Unpaid Principal Balance 7,458us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance [1]   7,568us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance [1]
Average Recorded Investment 6,775us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment 13,182us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment  
Recorded Investment 6,395us-gaap_ImpairedFinancingReceivableRecordedInvestment   6,386us-gaap_ImpairedFinancingReceivableRecordedInvestment
Interest Income Recognized 41us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod 38us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod  
Cash Basis Recognized 41us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod 40us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod  
Commercial and Industrial Loans and Leases      
With No Related Allowance Recorded:      
Unpaid Principal Balance 288us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
[1]   1,887us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
[1]
Recorded Investment 263us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
  1,877us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
Average Recorded Investment 324us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
2,135us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
 
Interest Income Recognized 3us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
30us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
 
Cash Basis Recognized 3us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
33us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
 
With An Allowance Recorded:      
Unpaid Principal Balance 1,897us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
[1]   84us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
[1]
Recorded Investment 1,902us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
  87us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
Allowance for Loan Losses Allocated 129us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
  87us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
Average Recorded Investment 1,934us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
4,371us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
 
Interest Income Recognized 23us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
1us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
 
Cash Basis Recognized 25us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
1us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_CommercialAndIndustrialLoansandLeasesMember
 
Commercial Real Estate Loans      
With No Related Allowance Recorded:      
Unpaid Principal Balance 1,660us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
[1]   1,944us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
[1]
Recorded Investment 1,282us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
  1,447us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Average Recorded Investment 1,484us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
2,433us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
 
Interest Income Recognized 11us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
3us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
 
Cash Basis Recognized 11us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
2us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
 
With An Allowance Recorded:      
Unpaid Principal Balance 3,613us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
[1]   3,653us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
[1]
Recorded Investment 2,948us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
  2,975us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Allowance for Loan Losses Allocated 1,450us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
  1,455us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Average Recorded Investment 3,033us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
4,243us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
 
Interest Income Recognized 4us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
4us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
 
Cash Basis Recognized 2us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
4us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
 
Agricultural Loans      
With No Related Allowance Recorded:      
Unpaid Principal Balance 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
[1]   0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
[1]
Recorded Investment 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
  0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
Average Recorded Investment 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
 
Interest Income Recognized 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
 
Cash Basis Recognized 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
 
With An Allowance Recorded:      
Unpaid Principal Balance 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
[1]   0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
[1]
Recorded Investment 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
  0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
Allowance for Loan Losses Allocated 0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
  0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
Average Recorded Investment 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
 
Interest Income Recognized 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
 
Cash Basis Recognized 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_AgriculturalMember
 
Subtotal      
With No Related Allowance Recorded:      
Unpaid Principal Balance 1,948us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
[1]   3,831us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
[1]
Recorded Investment 1,545us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
  3,324us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
Average Recorded Investment 1,808us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
4,568us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
 
Interest Income Recognized 14us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
33us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
 
Cash Basis Recognized 14us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
35us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
 
With An Allowance Recorded:      
Unpaid Principal Balance 5,510us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
[1]   3,737us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
[1]
Recorded Investment 4,850us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
  3,062us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
Allowance for Loan Losses Allocated 1,579us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
  1,542us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
Average Recorded Investment 4,967us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
8,614us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
 
Interest Income Recognized 27us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
5us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
 
Cash Basis Recognized 27us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
5us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= gabc_SubtotalMember
 
Loans Acquired With Deteriorated Credit Quality With No Related Allowance Recorded (Included in the Total Above)      
With No Related Allowance Recorded:      
Unpaid Principal Balance 190us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithNoRelatedAllowanceRecordedMember
[1]   289us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithNoRelatedAllowanceRecordedMember
[1]
Recorded Investment 90us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithNoRelatedAllowanceRecordedMember
  133us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithNoRelatedAllowanceRecordedMember
Average Recorded Investment 204us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithNoRelatedAllowanceRecordedMember
1,244us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithNoRelatedAllowanceRecordedMember
 
Interest Income Recognized 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithNoRelatedAllowanceRecordedMember
2us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithNoRelatedAllowanceRecordedMember
 
Cash Basis Recognized 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithNoRelatedAllowanceRecordedMember
2us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithNoRelatedAllowanceRecordedMember
 
Loans Acquired With Deteriorated Credit Quality With An Additional Allowance Recorded (Included in the Total Above)      
With An Allowance Recorded:      
Unpaid Principal Balance 747us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithAdditionalAllowanceRecordedMember
[1]   759us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithAdditionalAllowanceRecordedMember
[1]
Recorded Investment 197us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithAdditionalAllowanceRecordedMember
  209us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithAdditionalAllowanceRecordedMember
Allowance for Loan Losses Allocated 10us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithAdditionalAllowanceRecordedMember
  10us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithAdditionalAllowanceRecordedMember
Average Recorded Investment 298us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithAdditionalAllowanceRecordedMember
33us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithAdditionalAllowanceRecordedMember
 
Interest Income Recognized 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithAdditionalAllowanceRecordedMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithAdditionalAllowanceRecordedMember
 
Cash Basis Recognized $ 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithAdditionalAllowanceRecordedMember
$ 1us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ gabc_ImpairedFinancingReceivableAxis
= gabc_LoansAcquiredWithDeterioratedCreditQualityWithAdditionalAllowanceRecordedMember
 
[1] Unpaid Principal Balance is the remaining contractual payments inclusive of partial charge-offs.