XML 14 R46.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Common Stock and Dividends (Details) (USD $) | 0 Months Ended | 3 Months Ended |  |
--- | --- | --- | --- | ---
Apr. 17, 2015 | Apr. 09, 2015 | Oct. 15, 2014 | Apr. 18, 2014 | Mar. 31, 2015 | May 01, 2015 | Apr. 09, 2015
Common Stock and Dividends |  |  |  |  |  |  |
Series A cumulative perpetual preferred shares, outstanding |  |  |  |  | 216,000 us-gaap_PreferredStockSharesOutstanding |  |
Warrants to purchase entity's common stock (in shares) |  |  |  |  | 1,326,238 us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights |  |
Warrants, exercise price (in dollars per share) |  |  |  |  | $ 24.43 us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 |  |
Percentage of aggregate common stock investment on exercise of warrant to Senior Preferred Stock investment |  |  |  |  | 15.00%iboc_AggregateCommonStockInvestmentAsPercentageOfSeniorPreferredStockInvestmentOnExerciseOfWarrants |  |
Warrants, term |  |  |  |  | 10 years |  |
Cash dividends (as a percent) |  |  |  |  | 33.00%iboc_MaximumPercentageOfCashDividendsInExcess |  |
Cash dividends paid to common shareholders (in dollars per share) | $ 0.29 us-gaap_CommonStockDividendsPerShareCashPaid |  | $ 0.27 us-gaap_CommonStockDividendsPerShareCashPaid | $ 0.25 us-gaap_CommonStockDividendsPerShareCashPaid |  |  |
Repurchase of common stock, authorized amount |  |  |  |  | $ 40,000,000 us-gaap_StockRepurchaseProgramAuthorizedAmount1 |  | $ 40,000,000 us-gaap_StockRepurchaseProgramAuthorizedAmount1
Period of repurchase of common stock |  | 12 months |  |  | 12 months |  |
Cumulative number of shares repurchased under all stock repurchase programs |  |  |  |  |  | 8,684,680 iboc_StockRepurchaseProgramCumulativeSharesRepurchased |
Cumulative cost of shares repurchased under all stock repurchase programs |  |  |  |  |  | $ 257,704,000 iboc_StockRepurchaseProgramCumulativeCostOfSharesRepurchased |

X
- Definition The percentage of aggregate common stock investment on the exercise of warrant to the Senior Preferred Stock investment. + References No definition available. + Details
Name: | iboc_AggregateCommonStockInvestmentAsPercentageOfSeniorPreferredStockInvestmentOnExerciseOfWarrants
Namespace Prefix: | iboc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period representing the term of warrant. + References No definition available. + Details
Name: | iboc_ClassOfWarrantOrRightTerm
Namespace Prefix: | iboc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the maximum percentage of cash dividends in excess. + References No definition available. + Details
Name: | iboc_MaximumPercentageOfCashDividendsInExcess
Namespace Prefix: | iboc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cumulative cost of shares that have been repurchased under all stock repurchase programs as of a certain date. + References No definition available. + Details
Name: | iboc_StockRepurchaseProgramCumulativeCostOfSharesRepurchased
Namespace Prefix: | iboc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The cumulative number of shares that have been repurchased under all stock repurchase programs as of a certain date. + References No definition available. + Details
Name: | iboc_StockRepurchaseProgramCumulativeSharesRepurchased
Namespace Prefix: | iboc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(4)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(2)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph i -Subparagraph 2 -Article 4 + Details
Name: | us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate dividends paid during the period for each share of common stock outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_CommonStockDividendsPerShareCashPaid
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.28) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 + Details
Name: | us-gaap_PreferredStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Amount of stock repurchase plan authorized. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Period which shares may be purchased under a stock repurchase plan authorized by an entity's Board of Directors, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramPeriodInForce1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration