XML 46 R36.htm IDEA: XBRL DOCUMENT
v3.22.2

Allowance for Credit Losses (Aging By Loan Class) (Details) - USD ($) $ in Thousands | Jun. 30, 2022 | Dec. 31, 2021
--- | --- | ---
Financing receivable recorded investment |  |
Past due 90 days or Greater and Still Accruing | $ 8,230 | $ 8,642
Loans | 7,027,129 | 7,209,151
Current |  |
Financing receivable recorded investment |  |
Loans | 6,962,502 | 7,171,688
Total Past Due |  |
Financing receivable recorded investment |  |
Loans | 64,627 | 37,463
30 to 59 Days |  |
Financing receivable recorded investment |  |
Loans | 23,062 | 25,836
60 to 89 Days |  |
Financing receivable recorded investment |  |
Loans | 32,360 | 2,456
90 Days or Greater |  |
Financing receivable recorded investment |  |
Loans | 9,205 | 9,171
Commercial, financial and agricultural |  |
Financing receivable recorded investment |  |
Loans | 4,252,063 | 4,497,444
Commercial, financial and agricultural | Domestic | Commercial. |  |
Financing receivable recorded investment |  |
Past due 90 days or Greater and Still Accruing | 68 | 577
Loans | 1,475,364 | 1,501,852
Commercial, financial and agricultural | Domestic | Commercial. | Current |  |
Financing receivable recorded investment |  |
Loans | 1,471,325 | 1,498,438
Commercial, financial and agricultural | Domestic | Commercial. | Total Past Due |  |
Financing receivable recorded investment |  |
Loans | 4,039 | 3,414
Commercial, financial and agricultural | Domestic | Commercial. | 30 to 59 Days |  |
Financing receivable recorded investment |  |
Loans | 3,498 | 2,534
Commercial, financial and agricultural | Domestic | Commercial. | 60 to 89 Days |  |
Financing receivable recorded investment |  |
Loans | 440 | 303
Commercial, financial and agricultural | Domestic | Commercial. | 90 Days or Greater |  |
Financing receivable recorded investment |  |
Loans | 101 | 577
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial |  |
Financing receivable recorded investment |  |
Past due 90 days or Greater and Still Accruing | 1,314 | 307
Loans | 2,542,754 | 2,711,056
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial | Current |  |
Financing receivable recorded investment |  |
Loans | 2,532,434 | 2,692,076
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial | Total Past Due |  |
Financing receivable recorded investment |  |
Loans | 10,320 | 18,980
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial | 30 to 59 Days |  |
Financing receivable recorded investment |  |
Loans | 8,253 | 18,164
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial | 60 to 89 Days |  |
Financing receivable recorded investment |  |
Loans | 420 | 172
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial | 90 Days or Greater |  |
Financing receivable recorded investment |  |
Loans | 1,647 | 644
Commercial, financial and agricultural | Domestic | Commercial real estate: multifamily |  |
Financing receivable recorded investment |  |
Loans | 233,945 | 284,536
Commercial, financial and agricultural | Domestic | Commercial real estate: multifamily | Current |  |
Financing receivable recorded investment |  |
Loans | 233,750 | 284,536
Commercial, financial and agricultural | Domestic | Commercial real estate: multifamily | Total Past Due |  |
Financing receivable recorded investment |  |
Loans | 195 |
Commercial, financial and agricultural | Domestic | Commercial real estate: multifamily | 30 to 59 Days |  |
Financing receivable recorded investment |  |
Loans | 72 |
Commercial, financial and agricultural | Domestic | Commercial real estate: multifamily | 60 to 89 Days |  |
Financing receivable recorded investment |  |
Loans | 123 |
Obligations of states and political subdivisions |  |
Financing receivable recorded investment |  |
Loans | 1,733,234 | 1,668,113
Obligations of states and political subdivisions | Domestic | Commercial Real Estate: other construction and land development |  |
Financing receivable recorded investment |  |
Past due 90 days or Greater and Still Accruing | 34 | 188
Loans | 1,733,234 | 1,668,113
Obligations of states and political subdivisions | Domestic | Commercial Real Estate: other construction and land development | Current |  |
Financing receivable recorded investment |  |
Loans | 1,694,399 | 1,667,092
Obligations of states and political subdivisions | Domestic | Commercial Real Estate: other construction and land development | Total Past Due |  |
Financing receivable recorded investment |  |
Loans | 38,835 | 1,021
Obligations of states and political subdivisions | Domestic | Commercial Real Estate: other construction and land development | 30 to 59 Days |  |
Financing receivable recorded investment |  |
Loans | 8,133 | 499
Obligations of states and political subdivisions | Domestic | Commercial Real Estate: other construction and land development | 60 to 89 Days |  |
Financing receivable recorded investment |  |
Loans | 30,203 | 334
Obligations of states and political subdivisions | Domestic | Commercial Real Estate: other construction and land development | 90 Days or Greater |  |
Financing receivable recorded investment |  |
Loans | 499 | 188
Real estate - mortgage |  |
Financing receivable recorded investment |  |
Loans | 842,742 | 867,831
Real estate - mortgage | Domestic | Residential: first lien |  |
Financing receivable recorded investment |  |
Past due 90 days or Greater and Still Accruing | 5,452 | 4,937
Loans | 405,386 | 403,658
Real estate - mortgage | Domestic | Residential: first lien | Current |  |
Financing receivable recorded investment |  |
Loans | 397,059 | 394,975
Real estate - mortgage | Domestic | Residential: first lien | Total Past Due |  |
Financing receivable recorded investment |  |
Loans | 8,327 | 8,683
Real estate - mortgage | Domestic | Residential: first lien | 30 to 59 Days |  |
Financing receivable recorded investment |  |
Loans | 2,035 | 2,342
Real estate - mortgage | Domestic | Residential: first lien | 60 to 89 Days |  |
Financing receivable recorded investment |  |
Loans | 696 | 1,212
Real estate - mortgage | Domestic | Residential: first lien | 90 Days or Greater |  |
Financing receivable recorded investment |  |
Loans | 5,596 | 5,129
Real estate - mortgage | Domestic | Residential Junior Lien |  |
Financing receivable recorded investment |  |
Past due 90 days or Greater and Still Accruing | 1,328 | 1,055
Loans | 437,356 | 464,173
Real estate - mortgage | Domestic | Residential Junior Lien | Current |  |
Financing receivable recorded investment |  |
Loans | 435,226 | 462,256
Real estate - mortgage | Domestic | Residential Junior Lien | Total Past Due |  |
Financing receivable recorded investment |  |
Loans | 2,130 | 1,917
Real estate - mortgage | Domestic | Residential Junior Lien | 30 to 59 Days |  |
Financing receivable recorded investment |  |
Loans | 525 | 747
Real estate - mortgage | Domestic | Residential Junior Lien | 60 to 89 Days |  |
Financing receivable recorded investment |  |
Loans | 277 | 115
Real estate - mortgage | Domestic | Residential Junior Lien | 90 Days or Greater |  |
Financing receivable recorded investment |  |
Loans | 1,328 | 1,055
Consumer |  |
Financing receivable recorded investment |  |
Loans | 40,815 | 40,966
Consumer | Domestic |  |
Financing receivable recorded investment |  |
Past due 90 days or Greater and Still Accruing | 18 | 4
Loans | 40,815 | 40,966
Consumer | Domestic | Current |  |
Financing receivable recorded investment |  |
Loans | 40,459 | 40,643
Consumer | Domestic | Total Past Due |  |
Financing receivable recorded investment |  |
Loans | 356 | 323
Consumer | Domestic | 30 to 59 Days |  |
Financing receivable recorded investment |  |
Loans | 260 | 231
Consumer | Domestic | 60 to 89 Days |  |
Financing receivable recorded investment |  |
Loans | 78 | 88
Consumer | Domestic | 90 Days or Greater |  |
Financing receivable recorded investment |  |
Loans | 18 | 4
Foreign. |  |
Financing receivable recorded investment |  |
Loans | 158,275 | 134,797
Foreign. | Foreign |  |
Financing receivable recorded investment |  |
Past due 90 days or Greater and Still Accruing | 16 | 1,574
Loans | 158,275 | 134,797
Foreign. | Foreign | Current |  |
Financing receivable recorded investment |  |
Loans | 157,850 | 131,672
Foreign. | Foreign | Total Past Due |  |
Financing receivable recorded investment |  |
Loans | 425 | 3,125
Foreign. | Foreign | 30 to 59 Days |  |
Financing receivable recorded investment |  |
Loans | 286 | 1,319
Foreign. | Foreign | 60 to 89 Days |  |
Financing receivable recorded investment |  |
Loans | 123 | 232
Foreign. | Foreign | 90 Days or Greater |  |
Financing receivable recorded investment |  |
Loans | $ 16 | $ 1,574

X
- Definition Amortized cost of financing receivable 90 days or more past due and still accruing. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 16 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5111-111524 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 80 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922355-210448 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost, before allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953401-111524 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(3)(b)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 14 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919253-210447 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 80 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922355-210448 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher SEC -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (1) Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher SEC -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (2) Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher SEC -Name Regulation S-K (SK) -Number 229 -Section 1404 -Paragraph (a) + Details
Name: | us-gaap_NotesReceivableGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_PastDueFinancialInstrumentAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetNotPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables30To59DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables60To89DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=iboc_CommercialFinancialAndAgriculturalRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GeographicDistributionAxis=us-gaap_GeographicDistributionDomesticMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=iboc_CommercialRealEstateFarmlandAndCommercialReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=iboc_CommercialRealEstateMultifamilyReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LienCategoryAxis=us-gaap_SeniorLienMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LienCategoryAxis=us-gaap_JuniorLienMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=iboc_ForeignPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GeographicDistributionAxis=us-gaap_GeographicDistributionForeignMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |