XML 28 R30.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Fair Value Measurements (Details 3) (USD $) | Jun. 30, 2012 | Dec. 31, 2011
--- | --- | ---
Loans |  |
Carrying amount of fixed rate performing loans | $ 1,203,071,000 | $ 1,273,989,000
Estimated fair value of fixed rate performing loans | 1,137,384,000 | 1,200,837,000
Deposits |  |
Carrying amount of time deposits | 3,419,495,000 | 3,311,381,000
Estimated fair value of time deposits | 3,430,336,000 | 3,323,680,000
Securities Sold Under Repurchase Agreements |  |
Carrying amount of long-term repurchase agreements | 1,000,000,000 | 1,000,000,000
Estimated fair value of long-term repurchase agreements | 1,166,668,000 | 1,161,849,000
Junior Subordinated Deferrable Interest Debentures |  |
Carrying amount of fixed junior subordinated deferrable interest debentures | 20,619,000 | 87,630,000
Estimated fair value of fixed junior subordinated deferrable interest debentures | 11,340,000 | 43,403,000
Other borrowed funds |  |
Carrying amount of the long-term FHLB borrowings | 6,595,000 | 6,661,000
Estimated fair value of long-term FHLB borrowings | $ 7,142,000 | $ 6,998,000

X
- Definition Represents the aggregate of long-term FHLB borrowings reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with fair value disclosures required in footnote disclosures to financial statements. Such borrowings are initially due beyond one year or beyond the normal operating cycle, if longer. + References No definition available. + Details
Name: | iboc_FederalHomeLoanBankAdvancesLongTermFairValueDisclosure
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The carrying value of junior subordinated long-term debt with fixed rates of interest owed to unconsolidated subsidiary trusts as of the balance sheet date. Such debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets. + References No definition available. + Details
Name: | iboc_JuniorSubordinatedDebentureWithFixedRatesOfInterestOwedToUnconsolidatedSubsidiaryTrust
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Reflects carrying amount of loans charging borrowers fixed rates of interest. + References No definition available. + Details
Name: | iboc_LoansReceivableWithFixedRateOfInterest
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents the portion of fixed rate performing loans valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Fixed rate loan represents loans charging borrowers fixed rates of interest. + References No definition available. + Details
Name: | iboc_LoansReceivableWithFixedRateOfInterestFairValueDisclosure
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The carrying value as of the balance sheet date of securities that an institution sells and agrees to repurchase under a long term agreement (the identical or substantially the same securities) as a seller-borrower at a specified date for a specified price, also known as a repurchase agreement. + References No definition available. + Details
Name: | iboc_SecuritiesSoldUnderLongTermAgreementsToRepurchase
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Represents the portion of time deposits valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Time deposits include certificates of deposits, individual retirement accounts and open accounts. + References No definition available. + Details
Name: | iboc_TimeDepositsFairValueDisclosure
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_AdvancesFromFederalHomeLoanBanksAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DepositsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents a certain statement of financial position liability caption which represents a class of liabilities, or which may include an individual liability, measured at fair value on a recurring basis. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a),(b) -URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 01-6 -Paragraph 14 -Subparagraph f -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-DEP -Chapter 15 -Paragraph 37 -IssueDate 2006-05-01 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64702-112823 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 47 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher OTS -Name Federal Regulation (FR) -Number Title 12 -Chapter V -Section 563c.102 -Paragraph 15, 18 -Subsection I -LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy. Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822 + Details
Name: | us-gaap_FederalHomeLoanBankAdvancesLongTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrustAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_LoansAndLeasesReceivableNetReportedAmountAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. The amount of securities that an institution sells and agrees to repurchase (seller-borrower) at a specified date for a specified price, net of any reductions or offsets. Most repurchase agreements involve obligations of the federal government or its agencies, but other financial instruments, such as commercial paper, banker's acceptances, and negotiable certificates of deposit (CDs), are sometimes used in repurchase agreements. A repurchase agreement is similar to the seller-borrower's borrowing funds equal to the sales price of the related securities with the securities as collateral. Maturities of such agreements are flexible and generally vary from one day to 270 days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-DEP -Chapter 14 -Paragraph 4 -IssueDate 2006-05-01 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The aggregate amount of time deposits, including certificates of deposits, individual retirement accounts and open accounts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 9 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.12) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_TimeDeposits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant