XML 67 R49.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Financial Instruments with Off-Statement of Condition Risk and Concentrations of Credit Risk (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2024
Financial Instruments with Off-Statement of Condition Risk and Concentrations of Credit Risk |
Schedule of financial amounts of instruments, whose contract amounts represent credit risks | ​
​ | ​ | ​ | ​
Commitments to extend credit |  | $ | 3,440,252
Credit card lines | ​ | $ | 12,985
Standby letters of credit | ​ | $ | 147,435
Commercial letters of credit | ​ | $ | 2,108

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

X
- Definition Tabular disclosure of the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined) which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-10 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-11 + Details
Name: | us-gaap_ScheduleOfFairValueOffBalanceSheetRisksTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration