XML 61 R34.htm IDEA: XBRL DOCUMENT v2.4.1.9
Loans and Allowance for Loan Losses (Impaired Loans Disclosure) (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Financing Receivable, Impaired [Line Items]    
With no related allowance recorded, recorded investment $ 22,134us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment $ 26,631us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
With an allowance recorded, recorded investment 7,550us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment 7,851us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
Impaired Financing Receivable, Recorded Investment 29,684us-gaap_ImpairedFinancingReceivableRecordedInvestment 34,482us-gaap_ImpairedFinancingReceivableRecordedInvestment
With no related allowance recorded, unpaid principal balance 29,928us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance 35,196us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
With an allowance recorded, unpaid principal balance 8,289us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance 8,402us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
Impaired Financing Receivable, Unpaid Principal Balance 38,217us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance 43,598us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Related allowance 364us-gaap_ImpairedFinancingReceivableRelatedAllowance 418us-gaap_ImpairedFinancingReceivableRelatedAllowance
Purchased impaired loans with subsequent deterioration 105,662us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment 118,701us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance 107,857cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance 122,779cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
Purchased impaired loans with subsequent deterioration, related allowance 3,194us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment 3,237us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
Commercial and agricultural [Member]    
Financing Receivable, Impaired [Line Items]    
With no related allowance recorded, recorded investment 444us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
With an allowance recorded, recorded investment 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
498us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Impaired Financing Receivable, Recorded Investment 444us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
498us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
With no related allowance recorded, unpaid principal balance 493us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
0us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
With an allowance recorded, unpaid principal balance 0us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
498us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Impaired Financing Receivable, Unpaid Principal Balance 493us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
498us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Related allowance 0us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
58us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration 6,841us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
7,535us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance 5,521cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
6,149cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration, related allowance 239us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
257us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_CommercialAndAgriculturalPortfolioSegmentMember
Real estate - construction [Member]    
Financing Receivable, Impaired [Line Items]    
With no related allowance recorded, recorded investment 1,262us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
2,344us-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 1,262us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
2,344us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
With no related allowance recorded, unpaid principal balance 1,582us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
2,898us-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 1,582us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
2,898us-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 8,112us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
8,619us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance 9,234cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
9,855cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration, related allowance 783us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= cob_RealEstateConstructionPortfolioSegmentMember
507us-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 7,852us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
8,115us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
With an allowance recorded, recorded investment 3,738us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
3,294us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Impaired Financing Receivable, Recorded Investment 11,590us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
11,409us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
With no related allowance recorded, unpaid principal balance 9,761us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
10,238us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
With an allowance recorded, unpaid principal balance 4,305us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
3,676us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Impaired Financing Receivable, Unpaid Principal Balance 14,066us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
13,914us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Related allowance 353us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
331us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration 13,272us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
14,174us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance 14,078cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
15,278cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration, related allowance 240us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
199us-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 12,576us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
16,172us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
With an allowance recorded, recorded investment 3,812us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
4,059us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Impaired Financing Receivable, Recorded Investment 16,388us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
20,231us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
With no related allowance recorded, unpaid principal balance 18,092us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
22,060us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
With an allowance recorded, unpaid principal balance 3,984us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
4,228us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Impaired Financing Receivable, Unpaid Principal Balance 22,076us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
26,288us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Related allowance 11us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
29us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Purchased impaired loans with subsequent deterioration 76,489us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
87,345us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance 78,403cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
90,830cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Purchased impaired loans with subsequent deterioration, related allowance 1,744us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
2,085us-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 948us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
1,028us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
Purchased impaired loans with subsequent credit deterioration, unpaid principal balance 621cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
667cob_CertainLoansAndDebtSecuritiesAcquiredInTransferWithRelatedAllowanceForCreditLossesDueToSubsequentImpairmentUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
Purchased impaired loans with subsequent deterioration, related allowance $ 188us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
$ 189us-gaap_CertainLoansAndDebtSecuritiesAcquiredInTransferAllowanceForCreditLossesDueToSubsequentImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember