XML 20 R29.htm IDEA: XBRL DOCUMENT v2.4.1.9
Loans (Details 3) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Jun. 30, 2014
With an allowance recorded:          
Unpaid Principal balance $ 4,517us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance   $ 4,517us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance   $ 3,208us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Recorded Investment 4,516us-gaap_ImpairedFinancingReceivableRecordedInvestment   4,516us-gaap_ImpairedFinancingReceivableRecordedInvestment   3,202us-gaap_ImpairedFinancingReceivableRecordedInvestment
Allowance For Loan Losses Allocated 124us-gaap_ImpairedFinancingReceivableRelatedAllowance   124us-gaap_ImpairedFinancingReceivableRelatedAllowance   118us-gaap_ImpairedFinancingReceivableRelatedAllowance
Average Recorded Investment 3,046us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment 3,331us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment 2,977us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment 3,040us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment  
Interest Income Recognized 16us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod 9us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod 32us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod 24us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod  
Cash Basis Interest Recognized 16us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod 9us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod 32us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod 24us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod  
Commercial Loan [Member]          
With no related allowance recorded:          
Unpaid Principal Balance         0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
Recorded Investment         0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
Average Recorded Investment   3us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
  3us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
 
Interest Income Recognized   0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
  0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
 
Cash Basis Interest Recognized   0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
  0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
 
With an allowance recorded:          
Unpaid Principal Balance         0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
Recorded Investment         0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
Allowance for Loan Losses Allocated         0cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
Average Recorded Investment   0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
  15us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
 
Interest Income Recognized   0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
  3us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
 
Cash Basis Interest Recognized       3us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
 
Allowance For Loan Losses Allocated         0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
Other Commercial Real Estate [Member]          
With no related allowance recorded:          
Unpaid Principal Balance 2,973us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  2,973us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  1,642us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
Recorded Investment 2,973us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  2,973us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  1,635us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
Average Recorded Investment 1,502us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
1,480us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
1,426us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
1,009us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
 
Interest Income Recognized 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
 
Cash Basis Interest Recognized 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
 
With an allowance recorded:          
Unpaid Principal Balance 762us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  762us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  768us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
Recorded Investment 762us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  762us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  769us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
Allowance for Loan Losses Allocated 106cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  106cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  110cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
Average Recorded Investment 760us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
784us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
763us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
787us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
 
Interest Income Recognized 9us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
5us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
18us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
10us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
 
Cash Basis Interest Recognized 9us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
5us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
18us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
10us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
 
Allowance For Loan Losses Allocated 0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
Residential Real Estate Owner Occupied [Member]          
With no related allowance recorded:          
Unpaid Principal Balance 119us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  119us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  121us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
Recorded Investment 119us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  119us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  121us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
Average Recorded Investment 120us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
123us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
120us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
124us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
 
Interest Income Recognized 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
 
Cash Basis Interest Recognized 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
 
With an allowance recorded:          
Unpaid Principal Balance 125us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  125us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  127us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
Recorded Investment 125us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  125us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  127us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
Allowance for Loan Losses Allocated 4cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  4cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  4cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
Average Recorded Investment 125us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
279us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
126us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
280us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
 
Interest Income Recognized 2us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
4us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
 
Cash Basis Interest Recognized 2us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
4us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
 
Allowance For Loan Losses Allocated 0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
Residential Real Estate Non Owner Occupied [Member]          
With no related allowance recorded:          
Unpaid Principal Balance 74us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  74us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  472us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
Recorded Investment 74us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  74us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  472us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
Average Recorded Investment 74us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
121us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
37us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
132us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
 
Interest Income Recognized 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
1us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
2us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
 
Cash Basis Interest Recognized 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
1us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
2us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
 
With an allowance recorded:          
Unpaid Principal Balance 464us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  464us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  78us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
Recorded Investment 463us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  463us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  78us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
Allowance for Loan Losses Allocated 14cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  14cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  4cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
Average Recorded Investment 465us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
541us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
505us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
690us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
 
Interest Income Recognized 5us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
3us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
10us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
9us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
 
Cash Basis Interest Recognized 5us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
3us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
10us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
9us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
 
Allowance For Loan Losses Allocated $ 0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  $ 0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  $ 0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember