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v2.4.1.9

Allowance for Probable Loan Losses (Details 5) (USD $) | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
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Financing receivable recorded investment |  |  |
Past due 30-59 days | $ 17,261,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue | $ 19,891,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue |
Past due 60-89 days | 12,215,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue | 5,330,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue |
Past due 90 days or greater | 67,770,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue | 60,537,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue |
Past due 90 days or greater and still accruing | 9,988,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing | 7,197,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing | 15,033,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing
Past due, total | 97,246,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue | 85,758,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue |
Loans, current | 5,581,999,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent | 5,113,477,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent |
Total loans | 5,679,245,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome | 5,199,235,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome |
Commercial |  |  |
Financing receivable recorded investment |  |  |
Past due 30-59 days | 4,103,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember | 4,240,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember |
Past due 60-89 days | 2,665,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember | 538,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember |
Past due 90 days or greater | 40,665,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember | 36,066,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember |
Past due 90 days or greater and still accruing | 2,890,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember | 2,051,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember |
Past due, total | 47,433,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember | 40,844,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember |
Loans, current | 1,042,053,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember | 1,001,798,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember |
Total loans | 1,089,486,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember | 1,042,642,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_CommercialLoanMember |
Commercial real estate: other construction and land development |  |  |
Financing receivable recorded investment |  |  |
Past due 30-59 days | 596,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember | 1,042,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember |
Past due 60-89 days | 10,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember |  |
Past due 90 days or greater | 8,707,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember | 9,942,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember |
Past due 90 days or greater and still accruing | 439,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember | 62,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember |
Past due, total | 9,313,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember | 10,984,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember |
Loans, current | 1,405,664,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember | 1,197,524,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember |
Total loans | 1,414,977,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember | 1,208,508,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateOtherConstructionAndLandDevelopmentReceivableMember |
Commercial real estate: farmland and commercial |  |  |
Financing receivable recorded investment |  |  |
Past due 30-59 days | 2,905,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember | 6,216,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember |
Past due 60-89 days | 7,131,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember | 520,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember |
Past due 90 days or greater | 10,724,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember | 6,990,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember |
Past due 90 days or greater and still accruing | 1,711,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember | 417,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember |
Past due, total | 20,760,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember | 13,726,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember |
Loans, current | 1,880,639,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember | 1,736,313,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember |
Total loans | 1,901,399,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember | 1,750,039,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember |
Commercial real estate: multifamily |  |  |
Financing receivable recorded investment |  |  |
Past due 30-59 days | 351,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember | 39,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember |
Past due 60-89 days |  | 142,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember |
Past due 90 days or greater | 856,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember | 295,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember |
Past due 90 days or greater and still accruing | 21,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember |  |
Past due, total | 1,207,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember | 476,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember |
Loans, current | 115,492,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember | 101,622,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember |
Total loans | 116,699,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember | 102,098,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_CommercialRealEstateMultifamilyReceivableMember |
Residential: first lien |  |  |
Financing receivable recorded investment |  |  |
Past due 30-59 days | 5,895,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember | 4,758,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember |
Past due 60-89 days | 1,864,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember | 3,046,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember |
Past due 90 days or greater | 4,267,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember | 4,541,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember |
Past due 90 days or greater and still accruing | 3,901,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember | 3,518,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember |
Past due, total | 12,026,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember | 12,345,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember |
Loans, current | 410,000,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember | 426,117,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember |
Total loans | 422,026,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember | 438,462,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialFirstMortgageFinancingReceivableMember |
Residential: junior lien |  |  |
Financing receivable recorded investment |  |  |
Past due 30-59 days | 899,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember | 606,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember |
Past due 60-89 days | 231,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember | 198,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember |
Past due 90 days or greater | 1,931,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember | 1,900,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember |
Past due 90 days or greater and still accruing | 431,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember | 368,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember |
Past due, total | 3,061,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember | 2,704,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember |
Loans, current | 485,239,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember | 406,526,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember |
Total loans | 488,300,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember | 409,230,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ResidentialSecondMortgageFinancingReceivableMember |
Consumer Loan |  |  |
Financing receivable recorded investment |  |  |
Past due 30-59 days | 896,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember | 1,523,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember |
Past due 60-89 days | 216,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember | 469,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember |
Past due 90 days or greater | 507,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember | 803,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember |
Past due 90 days or greater and still accruing | 482,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember | 781,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember |
Past due, total | 1,619,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember | 2,795,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember |
Loans, current | 59,518,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember | 63,619,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember |
Total loans | 61,137,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember | 66,414,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_ConsumerLoanMember |
Foreign |  |  |
Financing receivable recorded investment |  |  |
Past due 30-59 days | 1,616,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember | 1,467,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember |
Past due 60-89 days | 98,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember | 417,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember |
Past due 90 days or greater | 113,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember |  |
Past due 90 days or greater and still accruing | 113,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember |  |
Past due, total | 1,827,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember | 1,884,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember |
Loans, current | 183,394,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember | 179,958,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember |
Total loans | $ 185,221,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember | $ 181,842,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = iboc_ForeignReceivablesMember |

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- Definition Financing receivables that are less than 60 days past due but more than 29 days past due. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953401-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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