XML 133 R69.htm IDEA: XBRL DOCUMENT v2.4.1.9
Loans and Allowance for Loan Losses (Impaired Loans Disclosure) (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Financing Receivable, Impaired [Line Items]    
With no related allowance recorded, recorded investment $ 26,631us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment $ 39,865us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
With an allowance recorded, recorded investment 7,851us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment 2,965us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
Impaired Financing Receivable, Recorded Investment 34,482us-gaap_ImpairedFinancingReceivableRecordedInvestment 42,830us-gaap_ImpairedFinancingReceivableRecordedInvestment
With no related allowance recorded, unpaid principal balance 35,196us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance 52,872us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
With an allowance recorded, unpaid principal balance 8,402us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance 3,032us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
Impaired Financing Receivable, Unpaid Principal Balance 43,598us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance 55,904us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Related allowance 418us-gaap_ImpairedFinancingReceivableRelatedAllowance 927us-gaap_ImpairedFinancingReceivableRelatedAllowance
Purchased impaired loans with subsequent deterioration 118,701us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment 161,307us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance 122,779cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance 172,301cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
Purchased impaired loans with subsequent deterioration, related allowance 3,237us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment 5,560us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
Commercial and agricultural [Member]    
Financing Receivable, Impaired [Line Items]    
With no related allowance recorded, recorded investment 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
398us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
With an allowance recorded, recorded investment 498us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Impaired Financing Receivable, Recorded Investment 498us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
398us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
With no related allowance recorded, unpaid principal balance 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
643us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
With an allowance recorded, unpaid principal balance 498us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Impaired Financing Receivable, Unpaid Principal Balance 498us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
643us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Related allowance 58us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration 7,535us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
10,729us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance 6,149cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
10,344cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration, related allowance 257us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
382us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Real estate - construction [Member]    
Financing Receivable, Impaired [Line Items]    
With no related allowance recorded, recorded investment 2,344us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
4,734us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
With an allowance recorded, recorded investment 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
Impaired Financing Receivable, Recorded Investment 2,344us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
4,734us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
With no related allowance recorded, unpaid principal balance 2,898us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
8,893us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
With an allowance recorded, unpaid principal balance 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
Impaired Financing Receivable, Unpaid Principal Balance 2,898us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
8,893us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
Related allowance 0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration 8,619us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
9,792us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance 9,855cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
11,216cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration, related allowance 507us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
1,015us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
Real estate - mortgage, 1-4 family residential [Member]    
Financing Receivable, Impaired [Line Items]    
With no related allowance recorded, recorded investment 8,115us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
11,154us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
With an allowance recorded, recorded investment 3,294us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
2,965us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Impaired Financing Receivable, Recorded Investment 11,409us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
14,119us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
With no related allowance recorded, unpaid principal balance 10,238us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
14,431us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
With an allowance recorded, unpaid principal balance 3,676us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
3,032us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Impaired Financing Receivable, Unpaid Principal Balance 13,914us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
17,463us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Related allowance 331us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
927us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration 14,174us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
26,628us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance 15,278cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
28,143cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration, related allowance 199us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
724us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Real estate - mortgage, commercial [Member]    
Financing Receivable, Impaired [Line Items]    
With no related allowance recorded, recorded investment 16,172us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
23,579us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
With an allowance recorded, recorded investment 4,059us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Impaired Financing Receivable, Recorded Investment 20,231us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
23,579us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
With no related allowance recorded, unpaid principal balance 22,060us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
28,905us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
With an allowance recorded, unpaid principal balance 4,228us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Impaired Financing Receivable, Unpaid Principal Balance 26,288us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
28,905us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Related allowance 29us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Purchased impaired loans with subsequent deterioration 87,345us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
113,178us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance 90,830cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
121,813cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Purchased impaired loans with subsequent deterioration, related allowance 2,085us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
3,251us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Consumer [Member]    
Financing Receivable, Impaired [Line Items]    
With no related allowance recorded, recorded investment 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
With an allowance recorded, recorded investment 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
Impaired Financing Receivable, Recorded Investment 0us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
With no related allowance recorded, unpaid principal balance 0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
With an allowance recorded, unpaid principal balance 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
Impaired Financing Receivable, Unpaid Principal Balance 0us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
Related allowance 0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration 1,028us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
980us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance 667cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
785cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration, related allowance $ 189us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
$ 188us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember