XML 19 R29.htm IDEA: XBRL DOCUMENT v2.4.1.9
Loans (Details 3) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 9 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Mar. 31, 2015
Mar. 31, 2014
Jun. 30, 2014
With an allowance recorded:          
Unpaid Principal balance $ 4,007us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance   $ 4,007us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance   $ 3,208us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Recorded Investment 4,006us-gaap_ImpairedFinancingReceivableRecordedInvestment   4,006us-gaap_ImpairedFinancingReceivableRecordedInvestment   3,202us-gaap_ImpairedFinancingReceivableRecordedInvestment
Allowance For Loan Losses Allocated 92us-gaap_ImpairedFinancingReceivableRelatedAllowance   92us-gaap_ImpairedFinancingReceivableRelatedAllowance   118us-gaap_ImpairedFinancingReceivableRelatedAllowance
Average Recorded Investment 4,105us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment 3,295us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment 3,352us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment 3,125us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment  
Interest Income Recognized 41us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod 14us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod 73us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod 38us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod  
Cash Basis Interest Recognized 41us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod 14us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod 73us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod 38us-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   1us-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
  10us-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   0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
  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 2,308us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  2,308us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  1,642us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
Recorded Investment 2,313us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  2,313us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  1,635us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
Average Recorded Investment 2,355us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
1,562us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
1,735us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
1,193us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
 
Interest Income Recognized 25us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
25us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
 
Cash Basis Interest Recognized 25us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
25us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
 
With an allowance recorded:          
Unpaid Principal Balance 708us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  708us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  768us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
Recorded Investment 708us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  708us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  769us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
Allowance for Loan Losses Allocated 77cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  77cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
  110cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
Average Recorded Investment 762us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
780us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
763us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
785us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
 
Interest Income Recognized 9us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
9us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
27us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
19us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
 
Cash Basis Interest Recognized 9us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
9us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
27us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_OtherCommercialRealEstateMember
19us-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 336us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  336us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  121us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
Recorded Investment 329us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  329us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  121us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
Average Recorded Investment 330us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
180us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
190us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
142us-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 123us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  123us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  127us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
Recorded Investment 124us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
  124us-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 124us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
178us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
125us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
246us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
 
Interest Income Recognized 2us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
2us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
6us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
2us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
 
Cash Basis Interest Recognized 2us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
2us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
6us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateOwnerOccupiedMember
2us-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 71us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  71us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  472us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
Recorded Investment 71us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  71us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  472us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
Average Recorded Investment 72us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
19us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
49us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
94us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
 
Interest Income Recognized 1us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
1us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
2us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
 
Cash Basis Interest Recognized 1us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
1us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
2us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
 
With an allowance recorded:          
Unpaid Principal Balance 461us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  461us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  78us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
Recorded Investment 461us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  461us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  78us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
Allowance for Loan Losses Allocated 11cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  11cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
  4cbkm_ImpairedFinancingReceivableWithRelatedAllowanceAllowanceForLoanLossesAllocated
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
Average Recorded Investment 462us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
575us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
490us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
652us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
 
Interest Income Recognized 4us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
3us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
14us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
12us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
 
Cash Basis Interest Recognized 4us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
3us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
14us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeCashBasisMethod
/ us-gaap_FinancialInstrumentAxis
= cbkm_ResidentialRealEstateNonOwnerOccupiedMember
12us-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