XML 28 R73.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Other Borrowed Funds (Details) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2012 | Dec. 31, 2011
Federal Home Loan Bank advances |  |
Balance at year end | $ 749,027 | $ 494,161
Federal Home Loan Bank advances short-term |  |
Federal Home Loan Bank advances |  |
Balance at year end | 742,500 | 487,500
Rate on balance outstanding at year end (as a percent) | 0.15% | 0.18%
Average daily balance | 412,919 | 733,559
Average rate (as a percent) | 0.19% | 0.19%
Maximum amount outstanding at any month end | 1,005,500 | 1,235,900
Federal Home Loan Bank advances long-term |  |
Federal Home Loan Bank advances |  |
Balance at year end | 6,527 | 6,661
Rate on balance outstanding at year end (as a percent) | 3.51% | 3.51%
Average daily balance | 6,590 | 6,721
Average rate (as a percent) | 3.51% | 3.51%
Maximum amount outstanding at any month end | 6,650 | 6,780
Amortization of long-term advances for the next five years | $ 149 |
Period of amortization of long-term advances | 5 years |

X
- Definition The annual amortization amount for Federal Home Loan Bank advances for the next five years. Update label as: Annual amortization of long-term advances for the next five years. + References No definition available. + Details
Name: | iboc_FederalHomeLoanBankAdvancesActivityForNextFiveYearsAmortization
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition This represents the period of amortization of the long-term advances in years. + References No definition available. + Details
Name: | iboc_PeriodOfAmortizationOfLongTermAdvances
Namespace Prefix: | iboc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages. + References Reference 1: 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 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher OTS -Name Federal Regulation (FR) -Number Title 12 -Section 563c.102 -Paragraph 18 -Chapter V -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 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-DEP -Paragraph 37 -IssueDate 2006-05-01 -Chapter 15 -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_AdvancesFromFederalHomeLoanBanks
Namespace Prefix: | us-gaap_
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
- Definition The calculated average balance outstanding for the year for all Federal Home Loan Bank advances as of the Balance Sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-DEP -Paragraph 17, 37 -IssueDate 2006-05-01 -Chapter 15 -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_FederalHomeLoanBankAdvancesActivityForYearAverageBalanceOfAgreementsOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The calculated weighted average interest rate for Federal Home Loan Bank advances outstanding as of the Balance Sheet date. + References Reference 1: 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 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-DEP -Paragraph 17, 37 -IssueDate 2006-05-01 -Chapter 15 -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_FederalHomeLoanBankAdvancesActivityForYearAverageInterestRateAtPeriodEnd
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The calculated weighted average interest rate for Federal Home Loan Bank advances for the period ended as of the Balance Sheet date. + References Reference 1: 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 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-DEP -Paragraph 17, 37 -IssueDate 2006-05-01 -Chapter 15 -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_FederalHomeLoanBankAdvancesActivityForYearAverageInterestRateForYear
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum balance outstanding at any month end during the period as of the Balance Sheet date. + References Reference 1: 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 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-DEP -Paragraph 17, 37 -IssueDate 2006-05-01 -Chapter 15 -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_FederalHomeLoanBankAdvancesActivityForYearMaximumOutstandingAtAnyMonthEnd
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant