XML 57 R46.htm IDEA: XBRL DOCUMENT
v3.19.1

Common Stock and Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands |  |  |  |  | 1 Months Ended |
--- | --- | --- | --- | --- | --- | ---
May 06, 2019 | Apr. 15, 2019 | Apr. 16, 2018 | Apr. 09, 2017 | Apr. 30, 2009 | Apr. 09, 2019
Common Stock and Dividends |  |  |  |  |  |
Cash dividends paid to common shareholders (in dollars per share) |  | $ 0.50 | $ 0.33 |  |  |
Repurchase of common stock, authorized amount |  |  |  |  | $ 40,000 | $ 50,000
Period of repurchase of common stock |  |  |  | 12 months | 12 months |
Cumulative number of shares repurchased under all stock repurchase programs | 9,801,561 |  |  |  |  |
Cumulative cost of shares repurchased under all stock repurchase programs | $ 311,359 |  |  |  |  |

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: | duration

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 Aggregate dividends paid during the period for each share of common stock outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -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 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

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