XML 40 R29.htm IDEA: XBRL DOCUMENT
v3.19.2

Fair Value (Fair Value Measurement and Assumptions) (Details) $ in Thousands | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2019 USD ($) | Jun. 30, 2019 USD ($) loan | Dec. 31, 2018 USD ($)
Assets: |  |  |
Impaired Loans | $ 14,287 | $ 14,287 | $ 14,306
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3 |  |  |
Charges to allowance for probable loan losses in connection with other real estate owned | 9,500 | $ 9,500 | 170
Number of loan foreclosures | loan |  | 1 |
Adjustment to fair value in connection with other real estate owned | 80 | $ 88 | 3,071
Impaired commercial collateral dependent loans | 14,287 | 14,287 | 14,306
Impaired commercial collateral dependent receivables appraisals to determine fair value within immediately preceding twelve months | 2,369 | 2,369 | 10,911
Impaired collateral dependent commercial loans with internal evaluation completed within last twelve months | 8,756 | 8,756 | 0
Measured on a non-recurring basis |  |  |
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3 |  |  |
Change in net provision, impaired loans | 1,133 | 1,133 | 356
Change in net provision, other real estate owned | 88 | 88 | 3,071
Change in net provision, equity investment without readily determinable fair value | 4,775 | 4,775 |
Measured on a non-recurring basis | Significant Unobservable Inputs (Level 3) |  |  |
Assets: |  |  |
Impaired Loans | 2,999 | 2,999 | 1,563
Equity investment without readily determinable fair value | 28,166 | 28,166 |
Non-financial assets: |  |  |
Other real estate owned | 26,703 | 26,703 | 38,871
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3 |  |  |
Impaired commercial collateral dependent loans | 2,999 | 2,999 | 1,563
Measured on a non-recurring basis | Assets/liabilities measured at fair value |  |  |
Assets: |  |  |
Impaired Loans | 2,999 | 2,999 | 1,563
Equity investment without readily determinable fair value | 28,166 | 28,166 |
Non-financial assets: |  |  |
Other real estate owned | 26,703 | 26,703 | 38,871
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3 |  |  |
Impaired commercial collateral dependent loans | $ 2,999 | $ 2,999 | $ 1,563

X
- Definition Amount of increase (decrease) of allowance reserve for credit losses in connection with loans transferred to other real estate owned. + References No definition available. + Details
Name: | iboc_AllowanceForLoanAndLeaseLossesPeriodIncreaseDecreaseLoansTransferredToOtherRealEstateOwned
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reflects the amount of charge-off related to a loan prior to foreclosure. + References No definition available. + Details
Name: | iboc_AllowanceForLoanLeaseLossesWriteOffsPriorToForeclosure
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The estimated fair value of recorded investment related to change in provision for equity investment without readily determinable fair value measured at fair value. + References No definition available. + Details
Name: | iboc_ChangeInProvisionOfEquityInvestmentWithoutReadilyDeterminableFairValue
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The estimated fair value of recorded investment related to change in provision for impaired financing receivables measured at fair value. + References No definition available. + Details
Name: | iboc_ChangeInProvisionOfImpairedFinancingReceivableFairValueDisclosure
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of change in Provision of other real estate and foreclosed assets. Other real estate may include real estate investments, real estate loans that qualify as investments in real estate. Foreclosed assets include all assets obtained in full or partial satisfaction of a debt arrangement through foreclosure proceedings. + References No definition available. + Details
Name: | iboc_ChangeInProvisionOfOtherRealEstateAndForeclosedAssetsInUse
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The impaired collateral dependent commercial loans where an internal evaluation has been done in the last twelve months. + References No definition available. + Details
Name: | iboc_ImpairedCollateralDependentCommercialLoansWithInternalEvaluationCompletedWithinLastTwelveMonths
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents the impaired commercial collateral dependent financing receivables where the basis for fair value is an appraisal obtained in the last twelve months. + References No definition available. + Details
Name: | iboc_ImpairedCommercialCollateralFinancingReceivableAppraisalsToDetermineFairValue
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The estimated fair value of the recorded impaired collateral measured on a non-recurring basis as of the reporting date. + References No definition available. + Details
Name: | iboc_ImpairedFinancingReceivableRecordedInvestmentFairValueDisclosure
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents the number of loans foreclosed on during the period. + References No definition available. + Details
Name: | iboc_NumberOfLoanForeclosuresDuringPeriod
Namespace Prefix: | iboc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Carrying amount as of the balance sheet date of other real estate and foreclosed assets. Other real estate may include real estate investments, real estate loans that qualify as investments in real estate. Foreclosed assets include all assets obtained in full or partial satisfaction of a debt arrangement through foreclosure proceedings. + References No definition available. + Details
Name: | iboc_OtherRealEstateAndForeclosedAssetsInUse
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Amount of investment in equity security without readily determinable fair value. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=116654751&loc=SL75117539-209714 + Details
Name: | us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |