XML 43 R67.htm IDEA: XBRL DOCUMENT v2.4.1.9

Allowance for Probable Loan Losses (Details 6) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Loan portfolio by credit quality indicator
Portfolio, total	$ 5,679,245us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome	$ 5,199,235us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
Pass
Loan portfolio by credit quality indicator
Portfolio, total	5,328,410us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember	4,942,387us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Special Review
Loan portfolio by credit quality indicator
Portfolio, total	54,561us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember	73,077us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Watch List - Pass
Loan portfolio by credit quality indicator
Portfolio, total	37,674us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_InternalCreditAssessmentAxis = iboc_SpecialPassMember	35,619us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_InternalCreditAssessmentAxis = iboc_SpecialPassMember
Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	182,429us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember	72,259us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	76,171us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember	75,893us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember
Commercial
Loan portfolio by credit quality indicator
Portfolio, total	1,089,486us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember	1,042,642us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember
Commercial | Pass
Loan portfolio by credit quality indicator
Portfolio, total	961,490us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember	955,522us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Commercial | Special Review
Loan portfolio by credit quality indicator
Portfolio, total	38,382us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember	2,270us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Commercial | Watch List - Pass
Loan portfolio by credit quality indicator
Portfolio, total	3,793us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember / us-gaap_InternalCreditAssessmentAxis = iboc_SpecialPassMember	4,389us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember / us-gaap_InternalCreditAssessmentAxis = iboc_SpecialPassMember
Commercial | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	45,646us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember	46,278us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Commercial | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	40,175us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember	34,183us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember
Commercial real estate: other construction and land development
Loan portfolio by credit quality indicator
Portfolio, total	1,414,977us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember	1,208,508us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember
Commercial real estate: other construction and land development | Pass
Loan portfolio by credit quality indicator
Portfolio, total	1,353,971us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember	1,167,295us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Commercial real estate: other construction and land development | Special Review
Loan portfolio by credit quality indicator
Portfolio, total	1,005us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember	14,247us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Commercial real estate: other construction and land development | Watch List - Pass
Loan portfolio by credit quality indicator
Portfolio, total	10,428us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember / us-gaap_InternalCreditAssessmentAxis = iboc_SpecialPassMember	9,318us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember / us-gaap_InternalCreditAssessmentAxis = iboc_SpecialPassMember
Commercial real estate: other construction and land development | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	38,697us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember	3,672us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Commercial real estate: other construction and land development | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	10,876us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember	13,976us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember
Commercial real estate: farmland and commercial
Loan portfolio by credit quality indicator
Portfolio, total	1,901,399us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember	1,750,039us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember
Commercial real estate: farmland and commercial | Pass
Loan portfolio by credit quality indicator
Portfolio, total	1,754,741us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember	1,635,179us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Commercial real estate: farmland and commercial | Special Review
Loan portfolio by credit quality indicator
Portfolio, total	11,674us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember	56,438us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Commercial real estate: farmland and commercial | Watch List - Pass
Loan portfolio by credit quality indicator
Portfolio, total	23,453us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember / us-gaap_InternalCreditAssessmentAxis = iboc_SpecialPassMember	21,912us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember / us-gaap_InternalCreditAssessmentAxis = iboc_SpecialPassMember
Commercial real estate: farmland and commercial | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	97,365us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember	20,472us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Commercial real estate: farmland and commercial | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	14,166us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember	16,038us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember
Commercial real estate: multifamily
Loan portfolio by credit quality indicator
Portfolio, total	116,699us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember	102,098us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember
Commercial real estate: multifamily | Pass
Loan portfolio by credit quality indicator
Portfolio, total	115,729us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember	100,948us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Commercial real estate: multifamily | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	135us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember	855us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Commercial real estate: multifamily | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	835us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember	295us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember
Residential: first lien
Loan portfolio by credit quality indicator
Portfolio, total	422,026us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember	438,462us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember
Residential: first lien | Pass
Loan portfolio by credit quality indicator
Portfolio, total	412,668us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember	432,067us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Residential: first lien | Special Review
Loan portfolio by credit quality indicator
Portfolio, total	3,500us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember	122us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Residential: first lien | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	18us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember	120us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Residential: first lien | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	5,840us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember	6,153us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember
Residential: junior lien
Loan portfolio by credit quality indicator
Portfolio, total	488,300us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember	409,230us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember
Residential: junior lien | Pass
Loan portfolio by credit quality indicator
Portfolio, total	484,968us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember	405,731us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Residential: junior lien | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	437us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember	293us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Residential: junior lien | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	2,895us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember	3,206us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember
Consumer Loan
Loan portfolio by credit quality indicator
Portfolio, total	61,137us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember	66,414us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember
Consumer Loan | Pass
Loan portfolio by credit quality indicator
Portfolio, total	59,622us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember	64,808us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Consumer Loan | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	131us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Consumer Loan | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	1,384us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember	1,606us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember
Foreign
Loan portfolio by credit quality indicator
Portfolio, total	185,221us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember	181,842us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember
Foreign | Pass
Loan portfolio by credit quality indicator
Portfolio, total	185,221us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember	180,837us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Foreign | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total		569us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Foreign | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total		$ 436us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_NonperformingFinancingReceivableMember

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- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5074-111524



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

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